The Treaty of Alcáçovas was signed in 1479 between the kingdoms of Portugal and Castile. It marked the end of the War of the Castilian Succession and established peace between the two powers. The treaty recognized Portugal's control over the Atlantic islands and granted Castile rights to the Canary Islands. Additionally, the treaty included provisions for the division of newly discovered lands. It set a boundary line in the Atlantic, which aimed to prevent conflicts over overseas territories. This agreement laid the groundwork for future exploration and colonization by both nations.