Christopher Columbus is known as Christophorus Columbus (in Latin), Cristoforo Colombo (in the Ligurian-Italian of his birth place) and and Cristóbal Colón in Spanish.
Christopher Columbus/Cristóbal Colón was born in 1451 in the Ligurian region of what is now Italy around the city of Genoa. He had a long career as a mariner and trader before his celebrated voyage across the Atlantic in 1492/1493. Prior to that, he had ranged from the Aegean to Ireland (quite possibly even to Iceland), and down the West Coast of Africa. He normally used Lisbon as his home port from 1477 to 1485.
In the late 15th Century, the Portuguese had been striving to find a way to directly trade for the spices and silks of Eastern Asia without having to pay the steep charges demanded by the Turkish Ottoman Empire. Their explatory voyages had made it to the Cape of Good Hope, the southern tip of Africa, by 1488.
Columbus proposed a different idea. Contrary to myth, European sailors and cartographers well understood that the world was round, but they had miscalculated the full distance of the circumfrence of the planet and had only a very vague idea of geography of most of Asia Columbus suggested pushing out directly west across the broad reaches of the Atlantic for a direct voyage to China and the far East.
Direct navigation across the Atlantic was extremely hazardous -- mostly because of the difficulties in carrying fresh water, fresh food, and firewood for a two to three month voyage. The Portuguese were heavily invested in the African route, and Columbus's proposal was rejected in 1485 and 1488, thereafter he approached other potential sponsors. The main resistance to his proposal was the (correct) view that Columbus had underestimated the circumfrance of the Earth. However, the Spanish proved willing and funded his historical voyage of 1492/93.