There is evidence for students having been taught at Oxford as far back as 1097AD. Although there is no known official date of foundation for the University, it grew rapidly from 1167 when King Henry II banned English students from attending the University of Paris. The first known foreign student, from what is now Germany, was taught there in 1190AD. The Aztec Empire was an alliance of three city-states in the Valley of Mexico. It was created in 1428AD and quickly conquered most of Central Mexico. During this same period Oxford was already well established as one of the pre-eminent seats of learning in the world. The Aztec Empire ruled until it was subdued by Spanish conquistadores and their native allies in 1521.