The Battle of St. Matthew's Day, fought between the Estonian forces under Lembitu and the Livonian troops led by Caupo of Turaida, was a pivotal conflict during the Livonian Crusade. Occurring near the Estonian town of Tallinn, this battle highlighted the ongoing struggle between the Christian Crusaders, who aimed to convert and subjugate the pagan peoples of the region, and the indigenous Estonian warriors, who sought to defend their land and way of life. The confrontation was characterized by its intensity, with both leaders being prominent figures in their respective communities and symbolizing differing ideologies and faiths.

Lembitu, a seasoned warrior and respected leader among the Estonians, had rallied his forces in defense against the encroaching Livonian order, which sought to expand their influence and territory. Caupo of Turaida, on the other hand, was a notable figure in the Livonian authority, representing the interests of both the local Germanic nobility and the wider crusading movement. Their deaths in battle marked a significant turning point, reflecting not only the volatility of the era but also the personal stakes involved in this larger geopolitical struggle. The aftermath of the battle led to a power vacuum, with shifts in local leadership and further challenges for the Estonian resistance.