The Battle of Matthew's Day () was fought near Viljandi (probably in Vanamõisa) on 21 September 1217 during the Livonian Crusade. The adversaries were the Sword Brethren (a German Crusading order) with their recently converted Livonian and Latgalian allies versus an army of 6000 Estonian men from different counties, led by Lembitu, who had attempted to unify the Estonians. The Germans won, although the converted Livonian chieftain Caupo of Turaida died. Lembitu was also killed, and many other Estonians were forced to convert. References Battles of the Livonian Crusade Battles involving Estonia Battles involving Livs Battles involving Letts Battles involving the Livonian Brothers of the Sword Battles in Estonia 1217 in Europe Conflicts in 1217 Viljandi County