noble adventurers who undertook its conquest and exploitation with their own means. The Isthmian region became the new centre of Spanish power and commerce in America. In 1513, Balboa crossed the Isthmus to the Pacific Ocean—an event second in its far-reaching consequences only to Columbus's first voyage. During the following years the Gulf of Mexico was explored, and in 1518 the greatest statesman and general whom Spain ever sent to the new world—Hernando Cortes—began the conquest of the empire of the Aztecs.