Frisian involvement in the Crusades

William of Tyre, drawing his information from Fulcher, mentions Frisians as part of the troops led by Godfrey at the Siege of Antioch in 1097–1098.

[3][4] With news of the fall of Edessa in 1144, a large force of Danes, Swedes, Scots, Welshmen, Englishmen, Normans, Frenchmen, Flemings, Germans, and Frisians assembled in connection with the Second Crusade about 200 ships, which left from Dartmouth in 1147 on the way to the Holy Land through the Straits of Gibraltar.

[5] A thirteenth-century legend praises the Frisian knight Poptatus Ulvinga from Wirdum, who was supposed to have led the siege with the help of a heavenly army under the command of Saint Maurice.

[6] In 1189, as they were en route to the Siege of Acre as a contingent of the Third Crusade, a fleet of Frisians, Danes, Flemings, and Germans, assisted by a small Portuguese presence, in about 50 ships attacked and took Alvor, massacring its Muslim inhabitants.

[12][13] Between the summer of 1228 and winter of 1231, Bishop Willibrand of Utrecht preached a crusade indulgence in Frisia, recruiting soldiers for his war against the heretical Drenthers.

They participated in the siege of Aachen and, on 3 November 1248, William, now crowned king of Germany, confirmed the rights and freedoms that had supposedly been granted them by Charlemagne.