The Universidad de Salamanca was founded by Alfonso IX in 1218, and, after the union of Castile and León, became the most important in Spain. Its rise to international stature was phenomenal, and within thirty years Pope Alexander IV proclaimed it equal to the greatest universities of the day. As at Oxford, Paris and Bologna, theories formulated here were later accepted as fact throughout Europe. The university continued to flourish under the Reyes Católicos, and in the sixteenth century it was powerful enough to resist the orthodoxy of Felipe II’s Inquisition, but eventually, freedom of thought was stifled by the extreme clericalism of the seventeenth and eighteenth centuries. Books were banned for being a threat to the Catholic faith, and mathematics and medicine disappeared from the curriculum. During the Peninsular War, the French demolished 20 of the 25 colleges, and by the end of the nineteenth century there were no more than three hundred students (compared to 6500 in the late sixteenth century). The university saw a revival in the early part of the twentieth century, particularly under the rectorship of celebrated philosopher and man of letters Miguel de Unamuno. Today, numbers are higher than ever (around 30,000 students) and Salamanca Uni has a certain social cachet, though academically it ranks well behind Madrid, Barcelona and Seville. It does, however, run a highly successful language school – nowhere else in Spain will you find so many young foreigners.