When it comes to the deradicalization of foreign terrorist fighters, Frisians – in this context, the modern regions of Ostfriesland and Land Wursten in Germany, and the provinces of Groningen and Friesland in the Netherlands – do not have a good track record and not much expertise to offer either. The only thing they can contribute to today's challenges of combating terrorism is to illustrate its destabilizing and destructive effects in Frisia during the High Middle Ages. Let's peer into the past. Let's go back to the era of the crusades and what happened in its aftermath. Because, when hiking the Frisia Coast Trail and everything is peaceful and quiet, understand that this land used to be a failed state at the Wadden Sea coast. Like standing on the shores of the Gulf of Aden today.

1. Fighters off to foreign lands

A novum was created by the Roman Catholic Church at the end of the eleventh century: the Holy War. Not just your average regular war, no, a holy one. A war to conquer the Holy Land. Creating the concept, frame, or truth – whatever you prefer – of a bellum iustum, a legitimate war. It was also a refined strategy of propaganda by the Church with the purpose of mobilizing knights and soldiers, and generating money to finance the costly endeavor that a war simply is. Despite being blessed, a holy war also has a hefty price tag. Crusades, therefore, are an example of complex planning and timing, communications and propaganda, and the generation of financial and human resources, etc. To quote Tyerman (2015):

The whole crusade-thing meant also a balance had to be found by the Roman Catholic Church between the pacifist Gospel on the one hand, and the need felt to defend Christianity with arms and violence on the other hand. Speaking less of the Commandment Thou shalt not kill, and more of thou shalt kill. No, not actually turning the other cheek (Matthew 5:38-40).

Deus vult 'God wills it'. Pope Urban II‘s successive call for battle and killing in 1095 against the Turks and the Arabs, and to conquer Jerusalem, had not been in vain. Crusade tax collectors, preachers, and legates were sent all over the lands of Europe to preach hate about Muslims and to get as many volunteers to take the Cross as possible. Back then, no entry visas were denied to these hate-preachers, to these Peter the Hermits. They travelled freely throughout Europe. 'Taking the Cross', by the way, was the common expression if one chose to join a crusade.

The transformation of monastic orders of hospice into military orders supported the crusades. The main orders were the Poor Fellow-Soldiers of Christ and of the Temple of Solomon (commonly known as the Order of the Knights Templar), the Order of Brothers of the German House of Saint Mary in Jerusalem (commonly known as the Teutonic Order), and the Order of Knights of the Hospital of Saint John of Jerusalem (commonly known as the Knights Hospitaller). The Teutonic Order and the Knights Hospitaller had a strong presence in Frisia as well, although their houses and monasteries were mainly inhabited by lay sisters. Not by the usual knights, since in Frisia no knighthood had developed anyway in the Middle Ages.

Knights Templar – It did not end very well for the Order of the Knights Templar. Despite their sacrifices for Rome and the Vatican, it was King Philip the Fair of France, with the consent of Pope Clement V, who accused the Knights Templar of heresy on Friday, October 13, 1307 – French rulers always had a way with spending money. Confiscating the properties of the Templars helped to supplement the king's empty treasury. The Order was dissolved; many were tortured, killed, and burned at the stake by the Inquisition. A big thank you for all their efforts during the crusades.

The revenues generated from arable land and other assets in Frisia, of the houses and monasteries, especially those of the Teutonic Order and the Knights Hospitaller, were taxed by their grand masters to finance the crusades. For example, in the present-day province of Groningen, in the region of Ommelanden, prosperous cloisters existed, like the one in the village of Warffum. In the High Middle Ages, we have a clear picture of this cloister. Its inhabitants were sixty nuns who were led by a female prior. This house possessed approximately 2,250 hectares of both arable and grassland. During the crusades, the revenues from the lands of the cloisters and religious houses were taxed to contribute to the wars.

Not only money was needed. Also men. Cannon fodder, we would call them today. The concept of a holy war worked very well with the young men of Frisia. The Roman Catholic Church even spoke of the "Frisones et Teutonici" marking the specific contribution of the Frisians within the German peoples. Again, meaning the Frisians from the present-day provinces of Friesland and Groningen, and of the regions of Ostfriesland and Land Wursten. So, everything between the sea strait 't Vlie and the River Weser.

The crusades

During the first crusade, from 1096 to 1099, no kings were involved on the battlefields, and therefore, there was no evident leadership. In total, there were four different armies. One of these armies came from northern France. Among the leaders of this northern French army was Count Robert II of Flanders, later nicknamed Robert of Jerusalem. Robert II eventually controlled a force of circa eight hundred knights and a few thousand foot soldiers. Among them were many Flemish and Frisian bowmen (De Maesschalck 2012). Count Robert II and his men fought in Syria, Lebanon, and Palestine, and together with the army of Godfrey of Bouillon, they conquered the sacred city of Jerusalem, the highest goal of the crusade. This is also how Robert II earned his illustrious nickname.

Frisians also participated in the second crusade, from 1145 to 1149. It was the Frisians, under the command of Popte Ulvinga (see further below), who led the way to take the city of Lisbon in Portugal.

Although they participated in the first two crusades already, with the third crusade the pope's call for battle had the full intended effect among the Frisians, and many took the Cross. This included a fleet leaving from the village of Blexen or Tettens at the Lower River Weser in the region of Butjadingen and Stadland (Blumenberg 2002). In modern terminology of the twenty-first century, many radicalized and became foreign fighters. During the third crusade, from 1189 to 1192, Landgrave Louis III of Thuringia gave the war horse of a defeated Saracen emir to a strong and brave Frisian leader (Savelkouls 2016). Hence, this testifies to the (noticeable) participation of Frisians during this crusade, too. And, of course, Frisians fought in the Battle of Damietta in Egypt during the fifth crusade from 1217 to 1221.

From 1097 until 1270, the Frisians fought in no less than seven crusades. Sometimes in Frisian maritime fleets of fifty or eighty so-called cog ships. Crusaders cruising the Mediterranean, but not on a holiday. They attacked, conquered, burned and sacked cities like Acre, Alcácer do Sal (i.e. Lisbon), Alvor, Antakya, Cadiz, Faro, Rota, Santiago, Silves, and even El Bahira in Tunisia. Sparing in many cities no mosque and no Muslim's life, not even those of civilians. Raiding the coast of the al-Andalus 'Andalucia' was a regular part of the itinerary when sailing to the Holy Land from the north, and in which the Frisian and Rhenish fleet played a big part, too. These raids fitted within the greater scheme of the Iberian Reconquista.

Concerning Tunisia, they were Frisians from the regions Ommelanden and Ostfriesland who assisted King Louis IX during the eighth crusade in the year 1270. The Battle of El Bahira in modern Tunisia in 1270, as described in the Cronica Floridi Horti, also gives a unique glimpse of how Frisian crusaders operated.

When they arrived with their ships from the island of Sardinia, the Frisians immediately wanted to confront the Saracen forces. This was because the Frisians, by nature, possessed not much patience. The crusade command barely was able to control the belligerent Frisian chapter, as was recounted. After the crusade army had taken its positions, the commander approached the Frisians like a hen approaches her chicks. He pleaded not to charge recklessly in front of the cavalry at the enemy, but to attack at the same time. This succeeded, and this is how the Frisians achieved a great victory. Next would be the attack on the strong city of Tunis in Tunisia. But here, seeing the impressive fortifications, the crusade command stalled. The Frisian forces, on the other hand, did not want to wait and waste their precious time on an unrealistic mission. They left with their cog ships for the Holy Land to fight. Note that the Frisians were not tied to any authority and thus were free to choose where and against whom they wanted to fight.

Especially the participation and deeds of the Frisians in the fifth crusade are quite well documented in contemporary texts. These are primarily the De itinere frisonum, part of the Chronicle of the monastery of Bloemhof 'Floridi Horti' at the village of Wittewierum in the modern province of Groningen, the Gesta crucigerorum rhenanorum, and the Chronicle of the Conquest of Damietta by Oliver of Paderborn. Oliver was a German cleric, later bishop of Paderborn, and he was relevant in recruiting fighters from the various Frisian lands. Oliver probably did not travel by sea with the Frisian and Rhenish fleet to the Holy Land, but made the journey overland instead. An impressive Frisian fleet of eighty cog ships departed in the year 1217 from the mouth of the River Lauwers, where today's village of Zoutkamp in the province of Groningen is located.

Half a century later, in the year 1269, another impressive fleet departed from Frisia. This time a fleet of fifty ships, departing from the island of Borkum in the modern region of Ostfriesland (Jansen & Janse 1991).

Converted to Christianity only relatively recently, the opportunity to join an army and to fight again apparently was a big pull for the young men of Frisia. Just as they had done before when volunteering for the ranks of the Roman Imperial Army (read our blog post Frisian mercenaries in the Roman Army for this piece of history) to fight the Picts on the British islands. Later again, joining the fleets and war bands of their northern cousins, the Vikings (read our blog post Foreign Fighters returning from Viking war bands and be filled with horror), causing havoc and tears for many coasts of western Europe. Or, lastly, Frisians manning the English fleet of King Alfred the Great to fight the very same Vikings (read our blog post ♪ They want you as a new recruit ♪).

The Roman Catholic Church knew exactly how to press the right buttons and spoke about "the honour of Christ that had been affected by the Saracens, i.e. Muslims from northern Africa, and the Mamluks." Or, in the words of Pope Innocent III (1161-1216), "perfidious Saracens." Honour was a very big thing back then, especially for the Frisians, a people still living in one of the last official feud societies of Europe. Of course, the full indulgences and booty promised by the Church contributed to their motivation, too.

During the crusades, the Frisians were known for their impatience and eagerness to fight and kill. In the year 1214, a contemporary wrote:

Stories have been passed on about Frisians leaving the battlefield to fight elsewhere when the crusade command stalled the attack too long. Like the night at the city of Faro in 1217, where the Frisians, because of their boisterous nature, and after having sung together, attacked the Saracen Army on their own during the night. And with success. The other chapters of the crusade army were still debating whether or not to attack.

The common thread running through thirteenth-century texts about the Frisian fighters was their impatience, their speed in charging at the enemy, and their ferocity during battle. They were real berserkers or barbarians. See further below, at the end of this blog post, how Frisian fighters were equipped and why, indeed, they were fast in charging at the enemy. Frisians in amente prevolans 'flying madly ahead', as it was written in a clear warning from Emperor Frederick I to his opponent Saladin, the sultan of Egypt, in the year 1188 (Mol 2002). In 1247, the king of France, in preparation for the seventh crusade, asked Pope Innocent IV to mobilize the Frisians to fight again (Jansen & Janse 1991). In 1250, Pope Innocent IV specifically called for the Frisians to participate in the seventh crusade because they had proven to be successful fighters in the Holy Lands. In the year 1268, when King Louis IX of France was preparing for the eighth crusade, he specifically encouraged the Frisians to join him.

It is clear Frisians had gained the reputation as accomplished and brave warriors during the twelfth and thirteenth centuries. Fighters who had conquered, among others, the cities of Lisbon and Damietta from the Saracens, and freed the city of Aachen from heretics (Janse 1991).

Concerning the siege of Aachen in the year 1248, Abbot Menko of the monastery of Wittewierum writes that after the armies of Brabant, Gelre, Hainaut, Holland, and Zeeland had besieged the city throughout the summer without success, the Frisians came to help. The Frisian chapter encamped in the open field before the city gate on the north-western side of the city. Thus far, none of the armies had dared to camp there. With this, Aachen was completely surrounded. After most of the city was flooded as well by damming the river through the works of the Frisians, the city surrendered. With the surrender of Aachen, Count William II of Holland could be crowned King of the Romans. For more about this piece of history, read our blog post Guerrilla in the Polder. The Battle of Vroonen in 1297.

At the same time, Frisian crusaders were realistic about what was achievable. When in the fifth crusade they were asked to take the strong city of Lisbon, the Frisians opposed to the Portuguese and the Dutch-Rhenish chapters of the crusade fleet, because they thought it would be too time-consuming both to take the great city and arrive in time in Italy. Fighting in the Levant was considered more priceworthy to them. Instead, the Frisian chapter left the fleet and continued to sail to the Mediterranean on its own, and successively raided the more manageable Muslim cities of Faro, Rota and Cadiz. The logic of the Frisian Alleingang might be explained by the fact they were participating primarily for their individual, personal benefit. To fulfil their vows. After all, as said, high-medieval Frisia was a republican affair without having feudal lords to obey.

In a way to mark their barbaric heroism, the – still-existing – Friezenkerk or Church of the Frisians in Vatican City was enlarged in the year 1141. To this very day, its pious Romanesque tower is the oldest in Vatican City, even in the eternal city of Rome as a whole. Amen. It stands opposite Saint Peter's Basilica. Read also our blog post Magnus' Choice: The Origins of the Frisian Freedom to learn more about the medieval history of Frisians in Rome and their own church.

Names of, partly alleged, Frisian foreign terrorist fighters have been recorded: Aylva, Beyma, Botnia, Cammingha, Fatema, Rainers lo Frison, Galama, Hermana, Hettinga, Jarich of Hogebeintum, Thithard Jelgera, Joulsma, Dodo Kempinga, Lambertus of Katrijp, Liauckema, Martena, Ockinga, Popta, Popte Ulvinga (or was Popte, in fact, Hendrik of Bonn, a German knight?) and, of course, the famous Roorda van Genum. The coat of arms of the Roorda family still bears a black Moor's head, as Roorda van Genum used to decapitate his opponents, or so it is told. The same Moor's head is depicted on the flag of Corsica. Check out our blog post Support of the Corsican Cause in Jeopardy – hiking the GR20 to understand more about these macabre, not too woke flags.

Crusader Hayo with the flail

Among the crusade tales, the most brutal of all was without a doubt Hayo de Violgama, also known as ‘Hayo with the flail’.

Hayo supposedly came from one of the many insignificant villages in rural Frisia, namely Wolvega, now in the province of Friesland. For the record, Wolvega, of course, is no longer insignificant. Others say Hayo came from the district of Fivelgo in the current province of Groningen. Whatever his exact place of origin, legend has it Hayo fought in the fifth crusade of 1217 and became famous for seizing the standard of the enemy during the battle against the Saracens in 1218. Apparently, standards were a highly valued commodity back then.

By the way, in the year 732, Frisians fought in the Frankish army in southern France against the Arabs, and one of these battles under the command of Saint Fris 'the Frisian' was named the Bataille de l'Étendard 'battle of the standard'; check our blog post Like Father, Unlike Son. Un saint frison en France. Indeed, what was the deal with those colours, banners, and flags?

Moreover, Hayo did not fight with a sword or spear. No, the trading mark of this religious fanatic was his Morgenstern 'flail' that he had taken with him from the farm (see image above). And it was Hayo who jumped first, or as the second since stories differ, onto the mighty tower of the city Damietta in the Nile Delta.

Although the story of Hayo is pure fiction, the siege of Damietta by a large Frisian fleet of cog ships is not. The Frisians, being a true maritime people, managed to convert their ships into an evenhoghe 'equally high'; a pontoon bridge as high as the Damietta tower. True knights of the sea (De Graaf 2004). And no, the citizens of the town of Haarlem in the province of Noord-Holland had no part in these fights at all, despite history lessons in high schools in the Netherlands teaching otherwise until quite recently, or even still. Instead, the people of Haarlem were friendly, law-abiding, nine-to-five citizens, earning a modest and honest living. Nothing like the rude raiders from Frisia raging in the Mediterranean. Take that as a compliment when reading this blog post. Nevertheless, the room of the Vroedschap, i.e. the medieval town council, in the old town hall of Haarlem is dedicated with impressive paintings to the fabricated heroic deeds of the people of Haarlem at Damietta.

Concerning Damietta, during the seventh crusade between 1248 and 1254, this port was a well-established Saracen pirate lair. In the year 1249, Damietta was briefly conquered by the Europeans but was handed back to the Egyptian Mamluks, after which Saracen pirates resumed their livelihood (Lehr 2022).

Crusader Popte Ulvinga

Crusader Popte Ulvinga, also known as Poppo or Poptetus Ulvinga, deserves elaboration, too. He came from the small village of Wirdum in the current province of Friesland. In the year 1147, during the second crusade, crusaders took part in the siege of the Moorish city of Lisbon in Portugal. The Moors were defeated. This victory is regarded as one of the turning points for the Reconquista of the Iberian Peninsula.

The German knight and crusader Henricus of Bonn died during this battle. At the spot where he was buried, miracles occurred. A palm tree on his grave was medicinal for whatever ailment people might have. When the remains of Poptetus were unearthed, they saw the palm tree had grown out from his heart. According to the journal of an unknown Frisian clergyman who travelled with the crusader's fleet to Acre in Palestine in 1217-1218, this palm tree, in fact, grew on the grave of Poptetus from Wirdum. Poptetus had renamed himself as Henricus, also written as Hendrik, and was the commander of the Christian army and bearer of the standard. So, Wirdum and not Bonn.

The journal of the unknown clergyman was incorporated into the thirteenth-century Cronica Floridi Horti 'chronicle of [monastery] Bloemhof'. Monastery Bloemhof, which translates as 'flower garden', was located near the village of Wittewierum in Frisia, of which Emo of Friesland, whom we mentioned earlier, was one of its founders. Abbot Emo of Friesland, by the way, was not a nobody but, among others, the first foreign student at the University of Oxford in 1190.

Fighting the Cathars

Besides fighting in the Mediterranean and the Levant, Frisians also participated in the crusade against the Cathars in southern France, especially in Occitania (Moolenbroek 2021). The Frisian word ketter and German Ketzer, meaning 'heretic', derive from the word Cathar. The civil war known as the Albigensian Crusade was heavily suppressed by the Roman Catholic Church. Catharism was a religious, dualistic Christian movement between the twelfth and fourteenth centuries, with a belief in a feminine god. A monk of the monastery of Saint Pantaleon in Cologne, probably in a light mood, reported that in the year 1212, many men from the regions of Saxony, Westphalia, and Frisia went off to fight the heretics in southern France. The prior of the monastery Saint James in the city of Liège in Belgium reported that in total 30,000 Frisians went to fight that year. This number, however, is probably a little too high to be realistic. But, mistakes can be made, especially when you are in such a light and euphoric mood seeing so many warriors setting off to slaughter unbelievers.

In the year 1210, the Frisians fought in a crusade army and took the strongholds of Minerve, near the great walled city of Carcassonne, and of Termes. A year later, Frisians fought at Cabaret, Lavaur, and Montgey. At Montgey, the crusaders were defeated, and 5,000 Germans and Frisians were slain. Although the tragedy at Montgey might also have involved the killing of 1,000 pilgrims, among them probably also Frisians. This slaughter might have been an additional motivation for Frisians to go berserk on the Cathars in the following years (Moolenbroek 2021). In the year 1212, Frisians successively participated in the sieges of the citadels of Saint-Antonin, Penne d'Agenais, Biron, and Moissac. Also, in the year 1213, Frisians fought in Occitania, only it is unknown where exactly. From the siege of Toulouse in 1217-1218, the name of a Frisian cavalryman has been preserved, namely Rainers lo Frison, also written as Rainaut lo Frizos. If you think Frisians serving in cavalry units is surprising, it actually is not. In our blog post Like Father, Unlike Son. Un saint frison en France you can read about a Frisian cavalryman who even became a saint.

A high-medieval, epic poem in the Occitan language, commonly known as Chanson de la croisade albigeoise, written by William of Tudela, who lived around 1200, and by an unknown writer, testifies to Frisians fighting against the Cathars. The lists of regions of provenance of the crusaders in the Chanson are long: Alaman e Bavier e Saine e Frison, Mancel e Angevi e Norman e Breton, Logombart e Lombart, Proensal e Gascon ('Germans and Bavarians and Saxons and Frisians, men from Maine and Anjou and Normans and Bretons, Langobards and Lombards, Provençals and Gascons'). But also:

They are the French, Normans, Bretons, and they are the Germans. the Lorrains and the Frisians, and they are the barons of Auvergne and the powerful Burgundians.

Other crusades

In the 1230s, Frisians also fought against rebellious Drents and Stedingers, i.e. the delta of the River Weser north of the city of Bremen. In the year 1248, as said, warriors of Frisia also participated in the siege of Aachen (Blumenberg 2002, Mol 2002).

The crusade in the year 1234 against Stedinger Land is saliant because it is this region at the Lower River Weser that was cultivated with the help of people from Holland who possessed the skills to exploit and peat and marshlands. We even know a few personal names of the first immigrant workers from Holland, See our blog post The United Frisian Emirates and Black Peat. How Holland became Dutch.

The Flussmarsch 'river marshes' of the region of Stedinger Land, Saxon in origin, had developed into a comparable republican structure as the neighbouring Frisian lands and Saxon region of Dithmarschen. For many years, the archdiocese of Bremen tried to gain control over the lands, but the free farmers effectively resisted the Bremen policy of expansion. In 1229, they even managed to kill the son of the brother of the archbishop during a great battle. A year later, Bremen had the Stedinger declared heretics by the pope. Still, Stedingen did not give in. Four years later, on 27 May 1234, a full-fledged crusade was launched. About 3,000 to 4,000 Stedinger fought against an army seven times their size and were, inevitably, defeated. It was the end of the people's freedom in the region of Stedingen. Many Stedinger fled north to the free Frisian regions of Stadland and Butjadingen (Wolff 2018). Hereafter, Bremen set its sights on Stadland and Butjadingen. Read in our blog post “Ich mag Ihre Pelzer- und Schustertöchter nicht!” – a kiss of death how badly that ended.

Like with the Cathars, you get the impression with the wars on the Stedinger that the Vatican was not really objective about who were declared heretic, and that more interests besides religion were involved. Getting further and further away from the pacifist Gospel and the Commandment Thou shalt not kill.

2. Fighters return from foreign lands

But all good things come to an end, eventually. At the end of the thirteenth century, after the last crusade, the Frisian foreign fighters, too, left the battlefields of Palestine, Livonia, Prussia, northern Africa, south-eastern France, Portugal, and southern Spain behind. For the tall big men of the north, as they were described together with the Danes at that time, the fighting and glory were over. Those cruisiati who had survived returned with their booty to their homeland, Frisia.

Once back in Frisia, they did not have to fear prosecution by the redjeva or grietman 'chosen judge and prosecutor' since what they did was not considered a (war) crime, yet. They had been soldiers of an honourable holy army, who had been fighting, killing, and beheading Muslims, Latvians, and Cathars, and raping their women, in a legitimate war. A bellum iustum. In other words, nothing to worry about. Back home, these veteran Frisian foreign fighters decorated themselves even with golden brooches made of Almohad 'Arabic' coins or copies thereof, to proudly mark that they had been fighting in the crusades in the Holy Land (Schokker 2018).

It was not over for the peoples living in the region we now call the Middle East, though. Almost eight centuries later, the Levant is still afflicted by ransacking, religiously motivated foreign terrorist fighters from all over the world, including some fighters from areas that belonged to former Frisia. Even practicing the same cruel methods as the Frisian havedling, also called Häuptling or hoofdeling in the German and Dutch languages respectively, Roorda van Genum allegedly did; beheading opponents. We bear in mind the coat of arms with a decapitated Moorish head.

The rehabilitation process of so many returning foreign fighters into the communal Frisian society became more than a concern. Absorbing this dangerous influenza went on for decades and decades, nearly for two centuries. The Roman Catholic Church, too, albeit slowly, became aware of the downsides of their successful radicalization programs. It was the patriarch in Palestine who in the year 1218 pointed out that crusaders had experienced great difficulties, not only in getting to Jerusalem, but also afterward. That is no rocket science or apple sauce. You can imagine. These outlaws were radicalized, partly war-traumatized men who had to be fit back again into rural society after often three years of fighting in foreign lands. Home meant nothing more than a modest living in a hamlet and doing humble labor. No glory, no status, no drinking bouts, and often no booty. Working the barren land in summer, strengthening dikes to keep land and houses protected from the sea in the windy and rainy months of autumn and winter.

Moreover, medieval Frisian society was exceptionally vulnerable to this deadly influenza as well. Frisia then, being a loose federation of free peasant republics stretching from the present-day province of Friesland to the region of Ostfriesland in the state of Lower Saxony. Unlike the rest of Europe, feudal structures were totally absent in Frisia at that time. Therefore, de-radicalization programs could not be organized, if they had thought about such programs at all.

On top of the homecoming of killing-happy foreign fighters, the myth of the so-called ‘Frisian Freedom’ fueled anarchy in Frisia. This freedom supposedly was granted to them by Charlemagne himself for – again – their heroic deeds in battle to liberate the city of Rome. A myth that told that the Frisians were free from then on, and not subordinated to any lord other than the Holy Roman Emperor himself. They were Reichsunmittelbar. Read our blog post Magnus' Choice. The origins of the Frisian Freedom for more detailed information about this history. All this, tipping over the already fragile balance between being a republic and anarchy. By the way, the free farmers' republics of Frisia, a feud society, were known as the Seven Sealands under the Treaty of the Upstalsboom (see further below).

The Republic Tradition – Nonetheless, the republican tradition of Frisia remained appealing and was picked up again with the foundation of the federation of the Dutch Republic at the end of the sixteenth century. Again a novum in Europe, next to the city of Venice. And February 1682, it was the States of Friesland, one of the republics within the Netherlands’ federation of Seven Republics, that voted as the second in the world, after France, to recognize the independence of the republic of the United States. Traditions in world history, when talking about republics: the Seven Sealands of Frisia, the United Seven Dutch Republics, the United States of America. Somewhere in between, a revolution in France marketing or selling ‘the republic’ as their noble contribution to the world. In fact, it produced Bonaparte soon after. Not doing much good to the republican state forms in Europe.

Read more about the close ties between Frisia, the United States, and the Anglo-Saxon world in general in our blog posts Porcupines Bore U.S. Bucks. The Birth of Economic Liberalism and History is written by the victors – a story of the credits.

Back to the High Middle Ages.

Reboelje 'turmoil' and civil war soon followed in Frisia. The fight between the Schieringers 'speakers' and the Vetkopers 'fat-buyers' started a few decades after the crusades had ended, around 1300. Flails, pitchforks, shovels, and alike were no longer solely working the land. At first, it was relatively small scale and localized, but a century later it had become a full-fledged civil war with warlords and armies from the River Vlie in the Netherlands to the River Weser in Germany. A period known as the Great Frisian War. Warlords called headmen; hovedling or hovetling in the Old Frisian language, haadlings in the Mid Frisian language, and Häuptlinge in the German language. This internal weakness left Frisia prey for its hostile neighbours who would soon feast on it. Ironically, these Teutonic neighbours were supported by the same Roman Catholic Church and its clergymen that had praised the sky for the Frisian achievements during the crusades, not long before. The thanks they got.

The free republics of the Seven Sealands of Frisia tried to organize themselves within a collective defense mechanism called the Treaty of Upstalsboom, similar to NATO seven centuries later. However, it failed completely. Read our blog post The Treaty of Upstalsboom: Why Solidarity Is Not the Core of a Collective. It is a fascinating history with relevant lessons for today, we think.

3. What did these warriors look like?

For those readers wondering what these foreign fighters must have looked like, please find below a mural from the church in the village of Westerwijtwerd in the province of Groningen, dating from the fourteenth century. It is thought to be a copy of a much older image, dating from the twelfth century. Indeed, the period of the crusades. Its church is still standing, although serious earthquakes due to heavy gas mining do threaten it anno 2019. Watch our vlog visiting the church of Westerwijtwerd.

Typical features of the twelfth and thirteenth centuries fighters of Frisia were the heavy long, fish-skin like coats made of leather strips (called a schobbejak in the Dutch language) and their heads shaved almost bold. The higher the hair was shaved off, the higher the status of the warrior.

...with sword and with spear and with the brown shield. (First Riustringer Codex)

Weapons they were carrying were: a small round shield, a sword, called a truchslayn in the Old Frisian language, and a long gaff annex spear called a kletsie or cletsie in the Old Frisian language. At the same time, this spear was used as a jumping pole to leap over the numerous ditches and small creeks in Frisia. Medieval images show that the spears had a disk or steel trident at the lower end. Just as, for example, the modern leaping poles, called a klootstock in the region of Nordfriesland, or polsstok in the Netherlands, are being used to this day. Therefore, one can reckon these spears were at least 3.5 or 4 meters long. In the German language, this weapon is called a Sprungspeer. Four of these steel tridents have been preserved in the Netherlands. For long, these tridents were regarded as candle holders for travel (Historiek 2022). In addition, the warriors did not wear helmets. Neither did they wear shoes. So, they were light and able to move and charge fast. ‘Naked’ as in unprotected, as they were described in the Middle Ages.

The long pole-spears bear resemblance with the well-known fifteenth-century Swiss pikes, but Frisians were using these spears much earlier. A report of the Battle of Kuinre against Holland in the year 1397, illustrates one of its functions. It recounts how the Frisians had driven their steel-tipped poles into a bulwark with the points facing upwards in a slant (Mol 2022). The steal trident made sure the spear would hold its position against the enemy. Our guess is that the name chevaux de frise 'Frisian horses', which were military defensive obstacles previously used in the US against cavalry, but till recently also known in the UK during railroad constructions to prevent people from walking onto the railway track, derives from the Frisian pike formations. In the Dutch language a cheval de frise is called a Friese ruiter 'Frisian horseman'.

Similar late-medieval murals concerning their appearance exist in other churches in the province of Groningen as well, namely those of Den Andel, Stedum, and Woldendorp. Walking barefoot was probably customary for the Frisians living at the salt marsh. A tradition that survived among the Frisians living at the Hallig islands in the region of Nordfriesland even until the nineteenth century (Knol 2021).

The image in the church of Westerwijtwerd corresponds with many more images of Frisian fighters on several seals of the Treaty of the Upstalsboom treaty, read our blog post The Treaty of Upstalsboom. Why solidarity is not the core of a collective, and of seals of Landesgemeinden or medieval districts like Rüstringen, Hunzingo-Oosterambt, Mormerland, Opsterland, and Oostergo. It also corresponds amazingly well with the written observation we referred to earlier in this blog post already, of a contemporary in the city of Liège in the year 1212, when he was watching Frisian warriors going to fight a holy war in the south of France:

Another contemporary, Bartholomeus Anglicus, wrote in his De Proprietatibus Rerum, written in 1240, that the Frisians are really different from their neighbours. All the men have shaved off their hair. The higher their hair is shaved off, the higher their status. Lastly, one of the last Free Frisians, was hovedling 'headman' Vibo Grovestins, nicknamed Skerne 'sheared' Wiebe from Engelum, who had his hair shaved off still in the late fifteenth century. A statement of Wiebe of the former glory days of the Frisian Freedom (Spiekhout 2022). A portrait of Skerne Wiebe, painted in the year 1472, has been preserved.

Note 1 – When Frisians in the year 1214 were motivated to take the Cross during the fifth crusade, a miracle happened at the villages of Bedum, Dokkum, and Wolvega in the province of Friesland. At Bedum, namely, a young girl saw Christ appear in the sky. Read our blog post Walfrid, You'll Never Walk Alone.

Note 2 – Know that the crusaders Poptetus Ulvinga, Dodo Kempinga, Thitard Jelgera, and Rainers lo Frison will probably be indicted by the International Criminal Tribunal of Frisia (ICTF) in the town of Aurich in the region of Ostfriesland. Read the Press Release about these provisional indictments by the ICTF.

Note 3 – Featured image, Capture of Damieta, Egypt.

Suggested music

Daliah Levi, Jerusalem (1972)

The Crusaders, Mischievous Ways (1987)

Army of Lovers, Crucified (1991)

Further reading

Barefoot Blogger, In search of the Cathars (2021)

Barreveld, J., Beards and Barbarians: Hair and identity in the Early Medieval West (2020)

Blumenberg, A., Butjadingen – Land und Leute – gestern und heute (2002)

De Maesschalck, E., De graven van Vlaanderen (861-1384) (2012)

Historiek, Friezen fierljepten vroeger ook op het slagveld (2022)

Janse, A., De waarheid van een Falsum. Op zoek naar de politieke context van het Karelsprivilege (1991)

Jansen, H.P.H. & Janse, A., Kroniek van het klooster Bloemhof te Wittewierum (1991)

Knol, E., For Daily Use and Special Moments: Material Culture in Frisia, AD 400-1000 (2021)

Lehr, P., Pirates. A new history, from Vikings to Somali raiders (2022)

Mol, J.A., De Friese volkslegers tussen 1480 en 1560 (2017)

Mol, J.A., Friese krijgers en de kruistochten (2001); Frisian Fighters and the Crusade (2002)

Mol, J.A., Vechten, bidden en verplegen. Opstellen over de ridderorden in de Noordelijke Nederlanden (2011)

Moolenbroek, van J., Friezen op kruistocht tegen de Katharen in Occitanië (2021)

Moolenbroek, van J., Nederlandse kruisvaarders naar Damiate aan de Nijl. Acht eeuwen geschiedenis en fantasie in woord en beeld (2016)

Nijdam, H., Lichaam, eer en recht in middeleeuws Friesland. Een studie naar de Oudfriese boeteregisters (2008)

Ottewill-Soulsby, S., Hair and the Heir: The Politics of Shaving in Eighth-Century Italy (2021)

Penning, Y., Emo’s labyrint (2010)

Pietersma, J. Friezen op kruistocht (1217-1221)

Readman, K., The Albigensian Crusade: Why did the Catholics start a civil war? (website)

Savelkouls, J., Het Friese Paard (2016)

Schokker, J., Insigne van een kruisvaarder? Over een pronkfibula gevonden nabij Uithuizen (2018)

Siefkes, W., Ostfriesische Sagen und sagenhafte Geschichten (1963)

Spiekhout, D., Brugge, ter A. & Stoter, M. (eds.), Vrijheid, Vetes, Vagevuur. De middeleeuwen in het noorden; Spiekhout, D., De pracht van middeleeuws Friese dracht (2022)

Tibble, S., Drunk and Disorderly: How Taverns Led Crusaders into Trouble (2025)

Tyerman, C., How to plan a crusade. Reason and Religious War in the High Middle Ages (2015)

Villegas-Aristizábal, L., A Frisian Perspective on Crusading in Iberia as Part of the Sea Journey to the Holy Land, 1217–1218 (2021)

Wiersma, J., Noord-Nederland na de bedijkingen (2018)

Wolff, S., Meine Heimat Butjadingen. Die Geschichte der Rüstringer Friesen (2018)