Christopher Columbus, October 1451 – 20 May 1506) was an Italian explorer, navigator, and colonist who completed four voyages across the Atlantic Ocean under the auspices of the Catholic Monarchs of Spain. He led the first European expeditions to the Caribbean, Central America, and South America, initiating the permanent European colonization of the Americas. He discovered the viable sailing route to the Americas, a continent which was not then known to the Old World.