Higher education as we know it today dates back to Medieval Europe — when the first universities were established. Today, the oldest existing degree-granting institutions are mostly located in four countries: France, Britain, Spain, and especially Italy, where papal decrees spread centers of knowledge that heralded the 400-year Italian Renaissance starting in the 1300s. The oldest university in the United States is Harvard University, which was founded in 1636, and is among the hardest colleges to get into.

That isn’t to say there weren’t earlier centers of learning elsewhere. The ancient Buddhist monastery of Nalanda in northeastern India, for example, passed on knowledge as far back as 500 A.D. until it was ransacked by invaders in the 13th century. The Madrasa Al Nizamiyya in Khargird, Iran, was founded in the 11th century as one of the first Islamic centers of knowledge. In fact, because of early Islam’s emphasis on teaching certain secular subjects like mathematics and geometry, the two oldest existing universities are Islamic schools in Morocco and Egypt.

Universities in the New World didn’t start to emerge until the 17th century so none made the list of the world’s 20 oldest universities that still exist today. The oldest university in Asia that still churns out graduates today is the University of Santo Tomas in Manila, founded in 1611 by a Catholic bishop, more than a century after the youngest university on this list.

Click here to read about the 20 oldest universities in the world.

24/7 Wall Street reviewed profiles of academic institutions of higher learning and cross referenced founding-date and enrollment number claims with university websites. In some cases we also cross-referenced information with higher-education oriented websites, mainly Times Higher Education and U.S. News and World Report. In some cases, the total student enrollment figures are estimates provided by the universities’ “About Us” pages, in others, they are from the higher-education oriented websites. Figures that aren’t estimates come from the latest available academic school year posted on the universities’ websites.