Which 1494 treaty divided overseas territories between Spain and Portugal?

The Treaty of Tordesillas divided overseas territories between Spain and Portugal in 1494.

Signed on 7 June 1494, the treaty moved a proposed line of demarcation west of the Cape Verde Islands. Lands discovered west of the line were assigned to Castile, while lands east of it were assigned to Portugal. The agreement attempted to prevent conflict between the two maritime powers during the Age of Discovery.

The treaty helps explain why Brazil became Portuguese-speaking while most of South America became Spanish-speaking. Portugal's side of the line included part of the eastern South American coast, although the precise boundary was difficult to determine with the geographical knowledge of the era.

Pope Alexander VI had earlier issued related decrees, but the Treaty of Tordesillas was a bilateral agreement between the Spanish and Portuguese crowns. The 1529 Treaty of Zaragoza later addressed competing claims in Asia.