The Alexandrian School was the foremost center of learning in the ancient world during the Hellenistic Age. Founded in 300 BC, and also known as the Museum (a place dedicated to the Muses), it housed the Alexandrian Library. The School was renowned from the outset, its teachers including the mathematicians Apollonius of Perga, Euclid, and Hero (or Heron); the physicians Erasistratus, Eudemus, and Herophilus; the geographer Eratosthenes; and the astronomer Hipparchus. The last great Alexandrian scientist was Claudius Ptolemy, who worked in the city between 127 AD and 151 AD. With decline of Hellenistic culture, activity in theSschool turned away from original research to compilation and criticism, the study of mystical philosophy and theology assuming an increasingly significant role.