| The Battle of Heiligerlee (Heiligerlee, Groningen, 23 May 1568) was fought between Dutch rebels and the Spanish army of Friesland. This was the first Dutch victory during the Eighty Years' War.The Groningen province was invaded by an army consisting of 3,900 infantry led by Louis of Nassau and 200 cavalry led by Adolf of Nassau. Both were brothers of William I of Orange.The Stadtholder of Friesland and also Duke of Aremberg, Johan de Ligne, had an army of 3,200 infantry and 20 cavalry.Aremberg initially avoided confrontation, awaiting reinforcements. However on 23 May, Adolf lured him to an ambush by Louis at the monastery of Heiligerlee. The ambush worked. The defending force lost 1,500â??2,000 men, while the invading force lost 50 men, including Adolf. The rebels captured seven cannons.The invading force did not capture any cities and was defeated at the Battle of Jemmingen.The death of Adolf of Nassau is mentioned in the Dutch national anthem (4th verse): Beginning of Eighty Years War |  |