Rex illiteratus est quasi asinus coronatus, ‘an illiterate king is like a crowned donkey’. Or, if you prefer the alternative translation, ‘an illiterate king is like a crowned arse’. These are almost thousand-year-old words of the bishop-philosopher-diplomat John of Salisbury, expressing the notion that kings and other rulers, in general, should be educated in order to fulfil their task. There is a small area in Frisia where its people choose and crown their kings during tournaments. It is the sport of kaatsen. Family of the palm game. In this blog post, we tell you more about this people's defying attitude or arrogance. And we disclose who is their emperor of kings, their friendly giant, their Donkey King.

1. Jeu de Paulme

The game kaatsen, also called Frisian handball or Frisian pelota, belongs to the big, extended family of jeu de paulme, often written too as jeu de paume, the palm game. The word kaatsen or keatsen derives from the Picardian word cachier or the French word chaser, meaning ‘to chase’. So, chasing the ball. Kaatsen is merely one of the many variants of the palm game that had developed in the region of Picardy in the northwest of France at the end of the twelfth century. Probably developed by monks as a kind of pastime or leisure. These innovative monks used the gallery roofs of their cloister garden to bounce the ball.

From the region of Picardy, the game spread over most of Western Europe. It became the appropriate game of the nobility, and over time it became popular under common people as well. The nobility built indoor courts to play jeu de paulme. The town square of Brugge in Belgium had one, just like Het Binnenhof in The Hague in the Netherlands had one too, for example. When hiking the Frisia Coast Trail, in the Dutch city of Haarlem the trail will pass one of the two remaining indoor courts left in the Netherlands, built in 1560 part of Castle Ter Kleef. The other remaining indoor court is part of Castle Bergh at the village of ‘s Heerenberg.

From the second half of the seventeenth century, jeu de paulme started to lose momentum in Europe. Other sports took over its place. High-end society started to kolven, a game played in the Netherlands already from the end of the thirteenth century. Looking both at the similarities of the game and of its name, it might be a predecessor of the now very popular sport golf. Especially from around 1900, people abandoned the centuries-old game of jeu de paulme. Except but one version, namely (lawn) tennis. It is therefore the proud daughter of the Picardian jeu de paulme. Wimbledon finales are being watched by millions and millions worldwide. The winner of Wimbledon goes home with three million dollar. The twelfth-century Picardian monks could only dream of these numbers, of spectators that is.

Indoor jeu de paulme has not disappeared completely from the face of the earth. Under the name real-tennis or courte-paume, the game is still being practiced in very similar indoor courts of back in the late-medieval days. Classic indoor courts exist in Australia, France, Ireland, the United Kingdom and the United States. But many other variants of jeu de paulme besides lawn tennis, real-tennis and kaatsen have survived, and are being practiced in many countries to date.

Start of the French Revolution – On June 20, 1789 the young Assemblée nationale gathered at the indoor court for jeu de paulme at the town of Versailles. It was here the people vowed that the Assemblée Nationale would not be dissolved before a new constitution was realized. This act in history is known as the Tennis Court Oath and considered the start of the French Revolution.

You basically have two elements that can be part of the game. The first one is a wall, a board, as is the case at the island of Lanzarote or, indeed, a roof. These are used to bounce the ball against. Like those innovative Picardian monks did centuries ago. Which financial analyst, banker or investor in the City, does not like to play squash with his colleagues after a hard days work? The other element that can be part of the game, is the use of an accessory for the hand to hit the ball harder. For example, with kaatsen a glove is used, except during serve, and in tennis a racket.

One of the versions of jeu de paulme that uses both wall and hand-accessory, has developed into the fastest ball-game of the world, namely jai-alai or cesta punta. Players use a handheld basket called a xistera or cesta, with which the solid ball can reach speeds of 300 km/h. The front wall needs to be of granite, otherwise it will be demolished in no time. No kidding. People even die playing this game. Hence its pet name ‘the game of dodging death’.

Jai-alai, the name used in the New World, developed in Argentina from Basque pelota, and spread into the Philippines and Latin America. It became a popular sport in Cuba, and spectators like the American writer Ernest Hemmingway enjoyed the game very much. Just as he liked tauromaquia ‘bullfighting’. From Latin America, jai-alai reached the United States. After the Cuban Revolution, jai-alai gained more popularity in (especially) the southern State of Florida with the influx of many Cuban refugees in the ’60s. But its popularity is also due to the sport was combined with gaming. Of the sixteen courts in the United States, ten are in Florida. And who does not remember the opening theme of Miami Vice in the ’80s?

Other variants of jeu de paulme still practiced today, exist in Europe too. Two types of jeu de paulme are/were being practiced in Belgium: jeu de pelote and jeu au tamis. The latter, however, is nearly extinct. In England a game called fives, with several variants, is related to jeu de paulme. It is also known as hand-tennis. In northern France the same types of jeu de paulme as in Belgium are/were practiced, and again jeu au tamis, also named balle au gant, is extinct too. Italy is still home to different kinds of jeu de paulme. These are palla elastica (or palla a mano), palla bracciale, tamburello and palla eh. The latter played in the region of Tuscany but, and it is getting tedious, almost extinct. In Ireland jeu de paulme exists still too. It is called liathróid láimhe, also known as Gealic handball. It is played mostly indoor nowadays. On the island of Gotland in Sweden a jeu de paulme variant called pärk is played, and is closely related to a (now extinct) version of kaatsen of southwestern Netherlands. Pärk is possibly introduced at Gotland via the Hanseatic League trade connections during the Late Middle Ages.

We mentioned jai-alai already. Stemming from the Basque version of jeu de paulme. The Basques, (still) locked inside the countries France and Spain, call their game pilota jakoa or just pilota. Basque pelota makes use of a wall too, called a pilotaleku or a frontón. Pelota also uses a racket, wooden bat or basket. From the sixteenth century onward, Basque pelota, or pelota Vasca, traveled with Basque emigrants to many countries in Latin America and to the United States. Cuban refugees made, as said, the sport popular in the State of Florida. But besides jai-alai, in the United States a game called (American) handball is played as well. It is a jeu de paulme variant making use of a wall. Again, there exists a variety of American handball games, mostly with differences in the number of players.

Under the banner of Wallball, different tournaments take place in Europe and even worldwide. There are European championships, a European Wallball Tour, a Wallball UK Open, a Netherlands’ National Championship Wallball, a national league US Wallball, et cetera. And, if we may believe their own reports of these events, popularity is increasing. But maybe it is preaching to the choir. Wait and see. In the village of Kimswerd in the province of Friesland a wall for wallball can be seen in the wild. Mostly without players.

2. The Kaatsen Game

As explained, jeu de paulme over time became popular among the common people too. In the Netherlands this was mostly combined with placing bets and alcohol. Hence its nickname kastelein-kaatsen ‘innkeeper’s kaatsen’. Players were challenged by hanging out a bird-claw holding a ball, the so-called kaatsklauw ‘kaatsen claw’. When someone accepted the challenge and a dual or match took place, bets were placed and money was to be earned. Comparable with how jai-alai became popular; with gaming.

The spot where the commons played kaatsen was often next to the inn or tavern in town. It regularly led to broken windows of the surrounding houses, to noise and evening quarrels. Because of the increasing nuisance, city councils started to regulate kaatsen in the Late Middle Ages, like designating the spots where people were allowed to play the game. Often outside the city (walls). Furthermore, squares next to churches were excluded and playing on Sundays as well.

Today kaatsen is actively practiced by around 10,000 people. That is the number of people who are member of the Royal Netherlands’ Kaatsen Union (KNKB). The KNKB has a budget of only ca. 0.6 million euro. Membership numbers show a steady decline from 1993, when the KNKB had around 18,000 members. With this trend, kaatsen will cease to exist in the year 2052. A painful and slow death. By then, the innkeeper of tavern De Bogt fen Guné (see further below) must have found a new source of income too. Even the Keatsmuseum ‘kaatsen museum’ in the town of Franeker, founded in 1972 to be prepared for the time when the sport has died out, is going through a laborious process. It closed down in 2014 and reopened in 2016, but still, few visitors. Laborious. While the solution is there for the taking, as the reader has noticed already: combine the sport with gaming!

If you think kaatsen is practiced throughout the province of Friesland, you got it all wrong. People from the peaty and sandy soils, i.e. the regions of De Wouden, Zuidwesthoek and Stellingwerven, only have limited interest for the sport. Not more than for a breakfast-bowl of oats in the evening, after having had dinner already. The northwest of the province of Friesland is the domain of kaatsen. It is where you stand on heavy clay. Check out our the map below where we have plotted the origin of kaatsen players participating at the PC tournament (for the PC, see further below) over the period 1854-2003.

When hiking the Frisia Coast Trail, you will notice you have entered kaatsen-country by the many wilted flower garlands hanging outside on fences, doors and walls of houses and farmsteads. It has nothing to do with commemoration of the dead. It are tokens that one of the residents is a successful kaatsen player. Count the garlands to know how successful. It provides the house or farm with status.

The beating heart of Frisian kaatsen is the town of Franeker. It is here where kastelein-kaatsen has a long-standing tradition. The first kaatsen court was on the eastern side of the town. Just outside the city walls. The street is still called Oud Kaatsveld ‘old kaatsen field’. Later, the court was relocated to the western side of town to a green named Kalahey. A name derived from Frisian keale hichte and meaning ‘barren heights’ and what is known now as It Sjûkelân. The name and sound Kalahey might be associated with empty vistas of the Highlands in Scotland but its elevation is just eleven meters above mean sea level. Just like the surroundings, by the way. Prove again, Frisians can be quite dramatic about elevations. In the eyes of every non-local, everything is as flat as a billiard table. Even flatter.

The green It Sjûkelân used to be the spot where Sjaerdemaslot ‘Castle Sjaerdema’ once stood for three centuries, until it was demolished in 1725. One of the owners of castle Sjaerdema was Carel van Sternsee. The terrain of the former castle was therefore also called the Sternse Slotland, from which somehow the name It Sjûkelân is derived.

Next to it Sjûkelân again is a tavern. The business' name is De Bogt fen Guné. 'the coast of Guinea'. The building is in use as a tavern alias café since the year 1641. De Bogt fen Guné, a name referring to questionable fortunes gathered with slavery and slave trade during the Dutch Republic (Guinea gold and slaves; Abulafia 2019), exists since 1664. In addition it may call itself the oldest student watering hole of the Netherlands. Since 1935 the three Frisian student associations from a few university towns in the Netherlands (i.e. Groningen, Delft and Wageningen) gather in tavern De Bogt fen Guné inn at the end of the year, to have a drink or two, or maybe a few more. However, the Corps Frisia in Germany and 't Selskip Frisia of the Groninger Studenten Corps Vindicat Atque Polit are still sorely missed. The student society D.S.F.S.S. Aldgillis from the town of Delft near The Hague struggles to survive with only a handful members left these days.

Nice anecdote. Famous philosopher René Descartes rented Castle Sjaerdema in the year 1629 while he was lecturing at the University of Franeker. A university now gone.

Silly Tourist - A fitting experience one of the Frisian bastards had in Italy in the autumn of 2010. After a short day-hike through the lower, forested slopes of the Alps near the villages of Torri and Collabassa, he was having a beer at a café-restaurant at Piazza Padre G. Mauro in the village Dolceacqua. A church square in town. Not paying attention because he was writing his journal, the piazza was meanwhile cleared from tables, chairs, cars etc. Windows shutters were being closed and benches were placed for audience. The bastard only noticed all this after people started to hit balls against the church wall. Indeed, the Frisian bastard was sitting in the middle of a jeu de paulme court. Everyone, audience and players, was waiting for the silly tourist sitting at the last remaining table on the square to finally notice and finish his beer. Quickly, and embarrassed, the bastard finished his beer and took a spot on the benches aligning the pitch.

The game seemed quite similar to that in the province of Friesland but the ball was bigger and softer, and the players used both their fists to bounce the ball.

Today, It Sjûkelân is the location where the biggest kaatsen tournament for men takes place every year: the PC. The abbreviation PC stands for Permanente Commissie ‘permanent committee’. Advice is to refrain from saying the full name Permanente Commissie if you want to live another day in Friesland. The PC was founded in 1853, With that it is the oldest sport tournament of the Netherlands. Do not ask why, but it takes place on the fifth Wednesday after the 30st of June. From 1854 onward always at It Sjûkelân. It is during this tournament the most coveted title of king is awarded. The best player of the tournament, whether in the winning team or not, is crowned king. The king receives besides a flower garland also a regal-like, silver king’s ball. The king’s ball is a challenge trophy, and should not be hanged on the outside of the house with the wilted garlands. The PC for women takes place every year in the village Weidum, the so-called Frouljus PC ‘women PC’. Here a queen is chosen. At present, the PC Queen of 2020 is Marrit Zeinstra. Hans Wassenaar is still king elected during the PC of 2019.

The reason why Hans Wassenaar is still king, is because in 2020 the PC had to be cancelled due to the COVID 19 pandemic. Is was the fifth time in its 167-years-old history that the PC has been cancelled. It is the second time due to an epidemic. In 1866 it was cholera.

Other important kaatsen tournaments are the Freule, which takes place in the village of Wommels, the Âld Meijerspartij in the village of Hitzum, and the Lanenkaatsen. The latter is the only tournament (still) played in town on the street, namely the Lanen St. in the town of Harlingen. The authentic, classic way to play the game. Then, of course, you have the National Championship and the European Championship.

By the way. We explained how the game of jai-alai arrived in the New World. But maybe the Dutch were earlier to introduce the game in the Americas. The State of New York, formerly the New Netherland colony, there are several toponyms referring to the game of kaatsen. These are Kaatsbaan, Katsban and Kaatserskill. All can be found in the valley of the River Hudson and must originate from around the mid seventeenth century.

3. The Greatest King: De Lange

Hotze Schuil. With a length of two meters, his nickname was De Lange ‘the tall one’. Although the people of the Netherlands’ North Sea coast are the tallest people in the world (read our blog post The Giants of Twilight Land), and two meters is thus not that exceptional, it is a height still being noticed.

Hotze started his kaatsen career when he was a kid. He stole a few cents from the wallet of his mother, hoping he would be able to return the money after winning the game without her noticing it. Of course, little Hotze did make a profit, and his mother did not notice. Again, combine kaatsen with gaming. It works, like we said earlier. Hotze was active in competition between 1942 until 1972, and he earned eighty-three king titles. A man who, just after he had started his kaatsen career, went through the five-days horrible bombing of the city of Hamburg in July 1943, after he had been send there as forced labor by the Nazis. Later, he survived another bombing, when the submarine bunker in Hamburg where he was working on, was hit by the Allies. That was April 1945. After that he fled in the chaos, and walked back home to his town Harlingen. The seed for the Frisia Coast Trail was sown.

Anyway, what the peloteros ‘players’ Pampi Laduche and Inaki Goikoetxea, alias Goiko, are for the Basques, is tall Hotze Schuil for the Frisians.

Hotze came from the fishing port of Harlingen, at the shores of the Wadden Sea. People from Harlingen speak a phenomenal singsong dialect, which is a blend of Mid-Frisian and Dutch languages. Harlingen people will be kind to you as long as you do not start to speak in Frisian to them. Their face is orientated toward the sea and their butt toward the land, as the phrase is locally. They greet each other consequently with “Hey Ouwe Seun“, meaning ‘old son’. If you say: “He is an Ouwe Seun” you mean to say the person is a citizen of Harlingen. But be precise. If you leave out ‘ouwe‘ and use only ‘seun’ something serious is coming up, like: “Hé Seun, si’k die ien de Súderhaven soademietere?” (Hey Son, shall I throw you in the southern sea docks?). Anyway, Hotze is the most famous Ouwe Seun of all.

Some non-locals might wonder if the Harlingen writer Simon Vestdijk is not more famous, with many books translated into foreign languages. The man who wrote faster than his shadow. More than two hundred books. To answer this popularity test, we took a look at the two statues in Harlingen relating to both men, to both Ouwe Seuns. In fact, Simon Vestdijk does not have his own statue at all. The only, tiny, statue is that of the boy Anton Wachter which stands at the Voorstraat St. Easy to overlook. It is a stiff-standing boy with his school bag under his arm. Anton Wachter is one of Simon’s, autobiographical, characters. Simon the kid. In stark contrast to Simon Vestdijk, Hotze Schuil has a real statue of himself. Bigger than life. More than three meters high. Of course, the man was already two meters tall in real life. A statue full of action and of energy. Serving the ball. And yes, Hotze is also more famous than the Harlingen vocal sisters Alie en Doetie de Vries.

Besides the title De Lange, Hotze also earned the titles Keizer onder kaatskoningen ‘emperor among kaatsen-kings’ and ‘Napoleon of the kaatsen sport’. That is not only because for long he held the overall classification record, until September 1990 when he was surpassed by Piet Jetze Faber. No, he was also the most ‘complete’ player, although primarily an opslager ‘server’. He was known as the schrik der opslagers ‘terror of the servers’.

Furthermore, Hotze had a striking appearance. Not only his length, but also the way he was dressed. He never stopped wearing the pre-WW2, traditional black leotards with a white shirt with collar. He also wore traditional black socks, instead of spikes. It gave him another nickname, held op sokken ‘hero on socks’. This was his appearance when all other players on the field were dressed in modern shorts, sport shoes, et cetera for years already. Through the years, Hotze had more and more difficulties to find new leotards once the old one was worn-out. And then his size. The true reason, by the way, why he kept wearing leotards was, according to himself, his white bony legs.

But maybe the biggest reason why Hotze has made a lasting impression was his sportsmanship and how he interacted with the public. Like many Ouwe Seuns, Hotze too loved the attention, loved the interaction, and liked to entertain. He was not too serious about anyone, including himself. He was communicative, relaxed, and humorous, also during the game. Even during the finals of the PC in Franeker, he was still relaxed. Moreover, he enjoyed his cigarette and his occasional drink, which were important ingredients for the seafaring folk of the port town of Harlingen. The café where you could find Hotze was former café bar Bambach at the Zuiderhaven ('southern docks') in Harlingen. It was also the hangout of a local named Blauwe Koos ('blue Koos'), a nickname Koos had earned because he always saw blue from liquor. The people of Harlingen love making nicknames (check our blog post Harbours, Hookers, Heroines and Women in Masquerade).

Anyway, all of this earned Hotze the support of the public. Or, as they say, he understood the psychological aspects of the game. This included, by the way, his insight into how his opponents acted. "The way they placed their feet gave away where the ball would fall," Hotze said. After he had stopped actively participating in kaatsen, Hotze refused to sit on benches at the grandstand. No, he sat on the grass next to the pitch. "I want to be in contact with the game," Hotze explained

.

When Hotze became ill and knew he would die, he said:

Well, the people made a bit of a hotch-potch after he died on November 25, 2005. They brought him to It Sjûkelân, the Kalahey, the Sternse Slotland in Franeker. Where Hotze had made fame (and no fortune) during the many PC tournaments. With a spade chairman of the PC Jan van der Meij cut a grass sod out the holy field, and put the sod on Hotze’s coffin. Van der Meij said: “This hole symbolizes the hole Hotze leaves behind. But this hole will fill itself and will turn green again. That is what will happen with us too, now that Hotze is no longer here. It is a hole in our mind. But also this hole will be filled again, with memories of and mementos from this special man.” Well spoken.

Note that cutting a turf, i.e. a clay sod, as a symbol of transition was a practice of the Frisians in the Roman Iron Age. When the Frisians were conquered -for a while- by the Romans, they offered a turf to the Romans. It meant they renounced their land. Not only did they give up the fertile soil that fed them but also everything that lay buried in it. All this, according to Pliny the Elder (AD 23-79) in his Naturalis Historia (Looijenga, et al 2017).

4. Why a king of kaatsen is a literate donkey

To play the game you must understand the rules. And these are truly complex. If you know how to play kaatsen, it must be you are very smart and thus suitable to pass the entrance exam of John of Salisbury to be king, and not an illiterate donkey. Below a summary, inspired by the KNKB website. We are curious if you get it! And if you dó understand the rules, you are permitted to go to Level 2, and try to understand the scoreboard of the game, called a telegraaf. Good luck!

Game material: leather ball of ca. 24 grams filled with hair and a kaatsen glove.

A kaatsen game is played on court A-B-C-D. It is a rectangular lawn of 61 meters by 32 meters.

Two teams play (a team is called a partuur) against each other. Each partuur consists of 3 players: 1 opslager (server) and 2 perkspelers (field players). Of the 2 perkspelers 1 must also serve. The ball must be struck by hand. As with tennis a ball may not hit the ground twice.

The opslagpartij, or serving team, (O) is positioned in zone C-D-E-F. Of the slagpartij, or receiving team, (X) 2 players are positioned in the slagperk a-b-c-d zone (i.e. receiving zone), while the third remaining player of the slagpartij is positioned in the field of the opslagpartij, so to be able to answer any action from the opslagpartij. After change of sides and functions this person takes care of the serve of his team.

One of the players of the opslagpartij (O) serves the ball (always with bare hand) to the slagperk zone a-b-c-d. After the opslagpartij (O) hits the ball into the slagperk zone a-b-c-d, the slagpartij (X) tries to return the ball. The slagpartij can wear gloves. The return of the ball must be done as far as possible. If it is possible over the line C-D (which is called boppe 'above'), otherwise as far as possible towards the line C-D. The ball must preferably be hit in a way that the opslagpartij (O) has no chance to bounce or return the ball. It is now the task of the opslagpartij to hit the ball back to or over the E-F line or, by timely blocking or hitting the ball back, to prevent the ball from penetrating far into the C-D-E-F zone. The task of the slagpartij (X), including the third person who’s outside the zone a-b-c-d of the slagpartij but is one of the slagpartij, is now again to prevent that the attempt by the opslagpartij (O) is successful. I.e. that the ball is returned to or on the line E-F.

Now there are 4 possible situations:

1. (1) The slagpartij (X) hits the ball over the line C-D. This means a win for the slagpartij (2 points).

2. (2) The slagpartij (X) failed to hit the ball past the E-F line. This means a win for the opslagpartij (O) (2 points).

3. (3) The opslagpartij (O) hits the ball back to or over the line E-F. This means a win for the opslagpartij (O) (2 points).

4. (4) The ball comes to a halt in the C-D-E-F zone. This is an undecided rally which is called a KAATS. The spot where the ball comes to a stop is marked with a white woodblock.

After change the new slagpartij (before change, the opslagpartij) must try to hit the ball further than the KAATS, which is indicated by the white woodblock. If this succeeds, 2 points will be awarded. If the new slagpartij does not succeed in hitting the ball past the KAATS, 2 points are awarded to the opslagpartij (the white woodblock will be removed). Change of fields and functions takes place after 2 KAATSs or, in some cases, after 1 KAATS (if one of the teams is on game point). The second KAATS is marked with a red woodblock.

Change of sides and of functions when:

1. At 2 KAATSs

2. At 1 KAATS when one of the teams has already gained 6 points. The latter to prevent that after winning an EERST (compare GAME) it is still necessary to compete for an undecided rally.

As with tennis, the points expire when one of the teams has achieved an EERST. For tennis the count is 15-30-40-GAME, when with keatsen the count is 2-4-6 EERST. Keatsen has no DEUCE. The first team to reach 6 EERST is the winner.

The slagpartij (X) wins 2 points:

1. By hitting the ball on or over the line C-D.

2. By hitting the ball farther than the KAATSs or KAATS hit before change.

3. If the opslagpartij does not serve the ball within the a-b-c-d zone. The lines of this zone do not belong to the zone of the slagpartij, therefore, when a serve lands on the line it counts as incorrect serve.

4. If the opslagpartij hits the ball directly outside the A-B-C-D zone.

5. If the opslagpartij hits a ball while the player is outside the lines or stands on one of the lines of A-B-C-D zone.

The opslagpartij (O) wins 2 points:

1. By preventing the slagpartij from hitting the ball further than the line E-F.

2. By hitting the ball hit out of the zone of the slagpartij back to on or over the E-F line.

3. By preventing the slagpartij from hitting the ball further than the KAATSs or KAATS hit before change.

4. If the slagpartij hits the ball directly outside of the A-B-C-D zone.

5. If the slagpartij hits a ball while the player is outside the lines or stands on one of the lines of A-B-C-D zone.

Further reading

Bangma, J., Jong, de A. & Joustra, W., De Lange. Hotze Schuil. Keizer onder de kaatskoningen (2006)

Bondt, de C., Royal tennis in renaissance Italy (2006)

Breuker, P., Acht eeuwen kaatsen: van Frans kloostervermaak tot Fries cultuurbezit (2008)

Breuker, P., Boppe! In blomlêzing út de Fryske keatsliteratuer (1987)

Breuker, P., Dijkstra, M., Janzen, J.P., Meij, van der J. & Wytsma, B. (eds.), De Fiifde Woansdei. 150 jier PC (1853-2003) 2003

Breuker, P., Hiddema, W., Tjepkema, K. & Yntema, D. (eds.), Kaatsen: lange traditie, levende sport. Bij het eeuwfeest (1897-1997) van de Koninklijke Nederlandse Kaatsbond (KNKB) (1997)

Erasmus, D., Colloquia Nicolaus Hieronymus (1520)

Francq van Berkhey, le J., Natuurlyke Historie van Holland (1773)

Gillmeister, H., Kulturgeschichte des Tennis (1990)

Historiek, De Eed op de Kaatsbaan (1789). Een Nationale Vergadering en een grondwet (2021)

Looijenga, A., Popkema, A. & Slofstra, B. (transl.), Een meelijwekkend volk. Vreemden over Friezen van de oudheid tot de kerstening (2017)

Speerstra, H., Kening op sokken (1983)

Urza, C., Historia De La Pelota Vasca En Las Americas (1994)

Vries, de A., Meagere kûten (2023)