While Greek ideas gradually permeated the Islamic world, Muslims conquests extended to the European continent. Spain was conquered by the Arabs around 700 AD, even reaching as far as Poitiers, France by 732 (Battle of Tours). By 902 Sicily was conquered. With the aid of Greek and other ideas, Spain in particular quickly became the most heavily populated and thriving area in Europe. One of the rulers of Muslim Spain, Al-Hakam II, made an effort to gather books from all over the Arab world, creating a library which would later become a center for translation into Latin.