Wijerd Jelckama

[4] Together with Pier Gerlofs Donia, Jelckama fought against the Saxon warriors that occupied their homeland of Frisia, at the capture of Medemblik, and in the siege of Middelburg castle.

In addition to the area occupied by the Saxons, parts of Frisia were conquered by Denmark, Holland, and local duchies.

[1] Under the leadership of Donia, they used guerilla tactics and gained several victories, including the successful siege of two Hollandic castles and the city of Medemblik.

[5] The rebels received financial support from Charles of Egmond, who claimed the Duchy of Guelders in opposition to the Habsburgs.

Jelckama and his soldiers took part in acts of piracy and sacked many villages in the Frisian lands, losing the trust and support of their own people.