The papal bull Aeterni regis [English: "Of the eternal king's [grace]"] was issued on 21 June 1481 by Pope Sixtus IV. It confirmed the substance of the Treaty of Alcáçovas, reiterating that treaty's confirmation of Castile in its possession of the Canary Islands and its granting to Portugal all further territorial acquisitions made by Christian powers in Africa and eastward to the Indies.