Damascius was born in Damascus in Syria, whence he derived his name: his Syrian name is unknown. In his early youth he went to Alexandria, where he spent twelve years partly as a pupil of Theon, a rhetorician, and partly as a professor of rhetoric. He was then convinced by his teacher Isidore to shift his focus to philosophy and science, and studied under Hermias and his sons, Ammonius and Heliodorus. Later on in life he migrated to Athens and continued his studies under Marinus, the mathematician, Zenodotus, and Isidore, the dialectician. He became a close friend of Isidore, succeeded him as head of the School of Athens in ca. 515, and wrote his biography, part of which is preserved in the "Bibliotheca" of Photius. In Athens he met Severianus of Damascus.