The Rulers of Frisia (Friesland)
 

From this wikipedia article:

Of the first historically verifiable rulers of Frisia, whether they are called dukes or kings, the last royal dynasty below is established by the chronicles of Merovingian kings of the Franks, with whom they were contemporaries. In these contemporary chronicles, they were styled dux, a Latin term for leader which is the origin of the title duke and its cognates in other languages (duc, duce, doge, duque, etc). They were independent until the death of Radbod at the earliest.
Finn, son of Folcwald, is a semi-legendary figure, but J. R. R. Tolkien (Finn and Hengest) is convinced that he was a historical ruler in the 5th century. He was killed by Hengest, who later migrated to Britain and founded the Kingdom of Kent. For rulers prior to Finn the later Frisians developed a rich store of legend and myth, and these too are listed here in chronological order.
After coming under Frankish rule the Frisians elected their own governors known as potestates. In the early 16th century Pier Gerlofs Donia, a legendary Frisian folk hero and freedom fighter, declared himself King of the Frisians, but died without succesors (his rebellion had been overrun, and the members of his war band, the Arumer Black Heap, were killed). After him, no man has ever assumed the title again.

In 775 the Franks under Charlemagne took control of what remained of Frisian territory and incorporated it into their kingdom, forcibly converting the Frisians to Christianity. In 800 Charlemagne became Holy Roman Emperor, and Frisia (or Friesland) remained under the sovereignty of the Holy Roman Emperors until the 16th century.

Counts


Appointed by the Frankish rulers to govern Frisia.

• Abba, 777-786 (Alfbad) (first Christian ruler of the Frisians)
• Nordalah, 786-806 (the last pagan stronghold, Ameland, fell in 806)
• Dirk, 806-810 (Radbod III)
• Godfrey, 810-839 (a Danish invader)
• Rorik, 839-875 (cousin of Godfrey)
• Gerulf I, 875-883
• Gerulf II, 883-916 (Friesland incorporated into the County of Holland in 922)

Potestates (fictive and real)


The potestate was a magistrate elected by the Frisians under the Holy Roman Empire.

• Magnus Forteman, fl. 809 (first recipient of the Karelsprivilege)
• Taco Ludigman, fl. c. 830 (Focko Ludigman) (protected the country against pirates)
• Adelbrik Adelen, fl. c. 830 (won a victory over a Swedish duke at Kollum)
• Hessel Hermana, 869-876 (a diligent warrior against the Vikings)
• Igo Galema, 876-910 (Ygo Galema)
• (vacant)
• Gosse Ludigman, 986-1000
• (vacant)
• Saco Reinalda, 1150-1167 (many Frisians were recruited into the crusades to the Holy Land)
• (vacant)
• Sicko Sjaerdema, 1237-1260 (Count William II of Holland offered him regional rule of Friesland)
• (vacant)
• Reinier Camminga, 1300-1306 (killed in the fight against "Danes Noertmannen ende")
• Hessel Martena, 1306-1313 (protected Friesland against the attacks of the counts of Holland)
• (vacant)
• Juw Juwinga, 1396 (Jonghema Ju) (killed in the Battle of Schoterzijl against Albert I, Duke of Bavaria)
• Sytse Dekama, 1397-?
• Gale Hania
• Odo Botnia, ?-1399
• Sjoerd Wiarda, 1399-1410 (elected by the Schieringers for Oostergo)
• Haring Haringsma, 1399-1404 (Haring Harinxma, or Haring Thoe Heeg) (elected by the Vetkopers for Westergo)
• (vacant)
• Juw Dekama, 1494-1498 (d. 1523) (only governed Oostergo)

Potestates (hereditary)


With the victory of the Schieringers against the Vetkopers, power passed to the dukes of Saxony.

• Albert, Duke of Saxony, 1498-1500 (appointed by Maximilian I, Holy Roman Emperor)
• Henry IV, Duke of Saxony, 1500-1505 (d. 1541)
• George, Duke of Saxony, 1505-1515 (d. 1539) (sold Friesland to Charles V, Holy Roman Emperor)

Kings


In rebellion against the forces of the Holy Roman Emperor.

• Pier Gerlofs Donia, 1515-1519 (d. 1520) (a farmer who declared himself King of the Frisians)
• Wijerd Jelckama, 1520-1523 (nephew of the former, beheaded in 1523 thus ending the monarchy)

Stadtholders


Originally stewards appointed by the Holy Roman Emperor, after 1581 the office of stadtholder became hereditary.

• Floris van Egmond, Count of Buren, 1515-1518
• Wilhelm van Roggendorf, 1518-1521
• Georg Schenck van Toutenburg, 1521-1540
• Jancko Douwama, 1522
• Maximiliaan van Egmond, Count of Buren, 1540-1548
• Jean de Ligne, Count of Arenberg , 1549-1568 (in 1556 sovereignty of Friesland passed to Philip II of Spain, son of Charles V)
• Karel van Brimeu, Count of Megen, 1568-1572
• Gillis van Berlaymont, of Hierges, 1572-1574
• Caspar de Robles, Heer van Billy, 1574-1576 (or 1572-1576)
• George van Lalaing, Count of Rennenberg, de Stadhouder-verrader, 1576-1581 (after 1580 in the service of Phillip II)
• Francisco Verdugo, 1581-1594 (in the service of Phillip II)
• Willem I van Oranje-Nassau, 1580-1584 (Friesland and six other provinces revolted in 1581 and formed the Dutch Republic)
• Willem Lodewijk van Nassau, 1584-1620
• Ernst Casimir, 1620-1632
• Hendrik Casimir I, 1632-1640
• Willem Frederik, 1640-1664
• Hendrik Casimir II, 1664-1696
• Johan Willem Friso of Orange, 1696-1711
• William IV of Orange, 1711-1751 (the seven provincial stadtholders within the Dutch Republic merged in 1747)
• William V of Orange, 1751-1795 (d. 1806) (Stadtholder-General of the Dutch Republic until it was destroyed by Napoleon)

Ah, how good someone added this! And here I see Pier Gerlofs Donia, he is in the article! Thats just fine! ;)

Well, they were actually put on wikipedia, which can be used freely as their text is free of copyrights (though to give them courtesy for it would be nice ;)). The idea is that we get more information on the Frisian rulers in this thread, when tie goes by.

most interesting.
I was reading about Baard-Baerd Friesland, came across Juw Dekema, and have found him listed here, thank you.Not to mention also on Wikipedia.