Inter caetera (‘Among other [works]’) was a papal bull issued by Pope Alexander VI on the 4 May (quarto nonas maii) 1493, which granted to the Catholic Monarchs Ferdinand and Isabella (as sovereigns of Castile) all lands to the “west and south” of a pole-to-pole line 100 leagues west and south of any of the islands of the Azores or the Cape Verde islands.[1]
It remains unclear to the present whether the pope intended a “donation” of sovereignty or an infeudation or investiture. Differing interpretations have been argued since the bull was issued, with some arguing that it was only meant to transform the possession and occupation of land into lawful sovereignty. Others, including the Spanish crown and the conquistadors, interpreted it in the widest possible sense, deducing that it gave Spain full political sovereignty.[2]
Inter caetera and other related bulls, particularly Dudum siquidem, comprised the Bulls of Donation.[3] While these bulls purported to settle disputes between Spain and Portugal, they did not address the exploratory and colonial ambitions of other nations, which became more of an issue after the Protestant Reformation.