Christopher Columbus organised four voyages into the New World. The first, in 1492, is by far the most famous. After this travel, he went to back to Spain to report on the voyage. He arrived to Lisbon, where he stayed and conversed with the King of Portugal, until his crew became angry, wanting to get back home, so eventually he went back to Palos. Afterwards, he went to Seville, where he remained for a short time, until he received a letter from the Catholic Monarchs ordering him to go to the Royal Court and report on his voyage. He arrived in Barcelona in the second half of April 1493, where he informed the Monarchs on what he saw. We don't know the details of this interview, but we can infer he was asked about the lands and whether he had made to the Indies, and Columbus' answer must have been something along the lines of "I don't have a clue". This lead to the immediate organisation of a second voyage, with an armada of 17 ships and 1,500 men. This second voyage set sail from Cádiz in the second half of 1493.

A third voyage, in 1498, was also organised by Columbus. He settled in Santo Domingo, acting in his capacity of Viceroy, Governor, and Captain General. His mismanagement, corruption, and brutality towards the Spanish settlers and the natives lead to the Crown sending a pesquisidor (attorney), who investigated the charges and brought Columbus back to Spain in chains. Bobadilla's inquiry resulted in Columbus being stripped of his ranks and titles, which caused Columbus to fall into bad economic shape, living off his wealthy mecenae, until he could reclaim his titles.

His fourth journey, this time under the Crown's orders and supervised by Juan Rodríguez de Fonseca Ulloa, was in 1502. After that, he remained in Spain, trying to fight the Crown for his titles and privileges, while helped by his mecenae and the Italian colony in Seville, more particularly his fellow Genovese people like Bartolomeo Fieschi, Franco Cattaneo, Francesco da Rivarola, and the Genovese ambassador.

In his final days he was in Valladolid, only accosted by his close friend Fieschi and some friars. He died there, on May the 20th 1506, being buried in the calasostra of Saint Francis' convent, under the patronage of the Duke of Medinaceli. He died in relative poverty, but he had the good taste of settling, in his last will, his old debts with Genovese people like Benedetto da Porto, Paolo de Negro, Lodisio Centurione Scotto, Nicolò Spinola di Luccoli di Ronco, and a couple other people.

His descendants managed to defeat the Crown in a very long series of lawsuits based on the concept of the Chapters of Santa Fe not being a Crown mercy but a contract, meaning the Crown could not unilaterally annul it without incurring in heavy penalties.

Edit: Forgot one thing. Columbus did participate in the slave trade. He sent 1,600 natives to Spain, of which 1,200 made it to their destination. This resulted in Columbus being condemned by the Crown to recover all of those people and bring them back to their lands at Columbus' expenses, as he was violating Queen Isabella's orders concerning the natives not being enslaved as they were vassals of the Crown of Castile. Not all of them were recovered, and it was rather notorious that amongst the great houses of Castile there were native American slaves. These slaves did not live long due to the rigours of the Spanish climate (especially in the Northern half of Spain), and the European sicknesses to which they were not immune.