In the 14th century, the Byzantine Empire fell. For the Christian West, this made trade with the Far East, usually for things like spices and gold, more difficult because sea routes were now under the control of less cooperative Arab and Italian merchants. As such, in the 15th and 16th centuries, the Spanish and Portuguese, and then the English and French, began to search for a new sea route. One method involved trying to bypass Africa. But, since the Europeans knew that the Earth was round, a second method involved traveling continuously West to circle the Earth. At the time, the Old World was not aware of the continent of America's existence and that it would be blocking the way. As such, in 1492, the Genoese navigator Christopher Columbus set sail West and became the first European explorer to discover America. Columbus' discovery became the cataclysm for the European exploration movement.