Christopher Columbus discovered the New World for the Kingdom of Castile and Leon in 1492. Private adventurers thereafter entered into contracts with the Spanish Crown to conquer the newly discovered lands in return for tax revenues and the power to rule. In the first decades after the discovery of the new lands, the Spanish colonised the Caribbean and established a centre of operations on the island of Cuba. By August 1521 the Aztec capital of Tenochtitlan had fallen to the Spanish. Within three years of the fall of Tenochtitlan the Spanish had conquered a large part of Mexico, extending as far south as the Isthmus of Tehuantepec. The newly conquered territory became New Spain, headed by a viceroy who answered to the king of Spain via the Council of the Indies.