Why did the Pope issue the Inter Caetera

The Papal Bull "Inter Caetera," issued by Pope Alexander VI on May 4, 1493, played a central role in the Spanish conquest of the New World. The document supported Spain’s strategy to ensure its exclusive right to the lands discovered by Columbus the previous year. It established a demarcation line one hundred leagues west of the Azores and Cape Verde Islands and assigned Spain the exclusive right to acquire territorial possessions and to trade in all lands west of that line. All others were forbidden to approach the lands west of the line without special license from the rulers of Spain. This effectively gave Spain a monopoly on the lands in the New World.