Jancko Douwama was a Frisian nobleman who fought to free Friesland from foreign rule. He was born in 1482 into a Vetkoper 'hoofdelingen' or 'untitled noble' family near Oldeboorn, Friesland. He was the son of the chieftain Douwe Douwama and his wife Riem Eesckes. Jancko was married to Teth Luersma.
Jancko Douwama is considered a hero of Frisian nationalism. Jancko Douwama lived in much troubled times during the final stages of a civil war in Friesland between the monastical factions called the Vetkopers and Schieringers. The Schieringers employed the assistance of the Saxon ruler Albrecht in 1498 gaining the upper hand over the Vetkopers. Douwama, a supporter of the Vetkopers, then began his fight against the Saxon overlord. He did this firstly from Groningen, where his wife came from and where he also had lived. In 1502 he returned to Friesland and recognized duke Albrecht in 1504 as its lord. Following the assassination of Albrecht in 1512 by the Vetkopers he escaped to Gelre and became employed by Charles, Duke of Guelders. Charles had long held plans to conquer Friesland.
In 1514 Douwama was leader of Charles' Guelder army that invaded Friesland. In 1517 disagreements between the Duke of Gelre and Jancko concerning the planning of the governing board of Friesland, and Gelre refusing to recognize Douwama as hereditary-lord eventually led to Jancko changing allegiances. In 1521 Jancko swore an oath of allegiance to the Holy Roman Emperor Charles V, the arch-enemy of the Duke of Gelre. The Frisians chose Jancko Douwama as their imperial stadtholder in 1522.
The emperor Charles V, however, suspected that Jancko was an infiltrator for the Gelderse and in 1523 Jancko was imprisoned in castle Vilvoorde, Belgium, where he died in 1533.
His names and actions are mentioned by the monk/historian Petrus Thaborita.
Whilst imprisoned in castle Vilvoorde, Jancko wrote his memoirs, titled the 'Boeck der Partijen' (Book of the Parties) which is considered one of the oldest written autobiographies. This historical essay discusses the origins of the discord between the warring parties in Friesland and of the activities of the author followed by a refutation of the charge of treason against the author. The memoirs gives Jancko's definition of the terms Schieringers and Vetkopers; 'Vetkopers' (fatbuyers) were so called because they had much and could buy fat products. The poor adopted the name 'Schieringers' because they had tried firstly discussion rather than violence. Because 'schieren' in Frisian means the same as 'to speak'. 'Schiering' means 'tale' and 'Schieringen' means 'many beautiful words'.
- Fryslan, staat en macht 1450-1650: Bijdragen aan het historisch congres te Leeuwarden van 3 tot 5 juni 1998. By Johan Frieswijk et al. Published 1999
- Douwama, Jancko: A man of honour. Anthology of the writings of Jancko Douwama, annotated by Martha Kist en Harmen Wind, 2003. Douwama, Jancko: Een man van eer.
- Egodocument of Jancko Douwama: Erasmus University Rotterdam
- 'Boeck der Partijen' (Book of the Parties), Jancko Douwama