'Inter Caetera' was a papal bull issued by Pope Alexander VI in 4 May, 1493, to stop fights between Spain and Portugal over territories in the new world. The document established a meridian 100 leagues west of Cape Verde Islands. Lands west of that line should belong to Spain, and those on the east, to Portugal.

The division was unequal. Spain heavily influenced the Bull, which excluded Portugal from Asia (Alexander VI was of Spanish origin himself). Reasoning behind the Bull was reward for service to the church. The Bull excluded other monarchs because of the reconquest. The Treaty of Tordesillas was a necessary followup. It moved the north-south line further west.

See also: Aeterni regis