Which treaty, signed in 1494, divided newly encountered lands between Spain and Portugal?

The Treaty of Tordesillas, signed in 1494, divided newly encountered lands between Spain and Portugal.

The agreement moved a previously proposed north–south demarcation line in the Atlantic westward. Lands east of the line were assigned to Portugal, while lands west of it were assigned to Castile, the principal Spanish kingdom involved in overseas expansion.

The treaty followed papal-backed negotiations after Christopher Columbus's 1492 voyage. It was intended to prevent conflict between the two Catholic maritime powers, though other European states did not accept its authority. The exact line was difficult to determine because longitude was hard to calculate accurately.

The arrangement helps explain why Brazil became Portuguese-speaking while much of the rest of South America became Spanish-speaking. The Treaty of Zaragoza, signed in 1529, later addressed competing claims on the opposite side of the globe.