Battle of Warns The Battle of Warns ( Frisian : " Slach by Warns " , Dutch : " Slag bij Warns " ) was a battle from the Frisian - Hollandic War between count Willem IV of Holland and the Frisians which took place on 26 September 1345 . The annual commemoration of the battle is important for many nationalist Frisians . Attack . After the Hollandic counts completed their conquest of West Frisia they planned the conquest of Middle Frisia , most of the present province of Friesland . In 1345 William IV , count of Holland , prepared a military action to conquer Middle Frisia , crossing the Zuiderzee with a large fleet and with the help of French and Flemish knights , some of whom had just returned from a crusade . He set sail in Enkhuizen to cross the Zuiderzee , together with his uncle John of Beaumont , and landed near Stavoren and Laaxum . They planned to use the Sint - Odulphus monastery near Stavoren as a fortification . The Hollandic knights wore armour , but had no horses as there wasn ' t enough room in the ships , which were full of building materials and supplies . William ' s troops set fire to the abandoned villages of Laaxum and Warns and started to advance towards Stavoren . In the countryside around Warns the Hollandic count was attacked by the local inhabitants . With their heavy armor the knights were no match for the furious Frisian farmers and fishermen . The path the Dutch knights choose to flee led straight to the Red Cliffs . As they fled they entered a swamp where they were decisively beaten . Their commander William IV of Holland was killed . When John of Beaumont heard what had happened , he ordered a retreat back to the ships . They were pursued by the Frisians and only a few made it to Amsterdam . Tactical Mistakes . The battle was marked by a number of tactical mistakes of the Dutch . First , they divided their forces in two . William landed north of Stavoren and his uncle Jan landed south . In addition , William continued the attack in haste without waiting for his archers . With a small group of 500 men he reached St . Odulphusklooster because the Frisians purposely moved back . But then they cut Willem from the bulk of his troops and defeated him . After Count Willem was destroyed they turned against his main troops that couldn ' t flee because the ships were offshore . When these troops were defeated , they attacked John of Beaumont . He hadn ' t participated until then . The Frisians could beat him because his camp was chosen poorly with the sea in the back so that his army could never retreat . The Frisians took the battle with the Dutch in the water where they beat them down . Commemoration . The Battle of Warns was annually celebrated on September 26 until the 16th century , than it moved to the last Saturday of September on which it is celebrated nowadays by nationalistic Frisians . There is a monument on the Red Cliffs in Warns since 1951 , a large glacial erratic with the text " leaver dea as slaef " [ sic ] ( rather dead than slave ) . The road to Scharl is still called the " ferkearde wei " ( the wrong way ) by the local inhabitants because this was the way the Dutch knights chose and led to their downfall . The Battle of Warnsveld was the inspiration for the historical novel " De Roos van Dekama " by Jacob van Lennep .