Ruled between 408-450, he was the son and successor of Arcadius. He preferred the study of theology and astronomy to public affairs leaving it to his sister Pulcheria and his wife Eudocia. The most important political events of his reign were the establishment of Valentinian III as emperor in the West in 425 and the raids into the Empire by the Huns under Attila. In 431, Theodosius summoned the Council of Ephesus, which condemned Nestorianism, and in 449 he convoked and upheld the Robber Synod, which declared the orthodoxy of Eutychianism. He also founded the Constantinople University in 425, declared the Theodosian Code (Codex Theodosianus) in 438, and restored the City Walls. Marcian, His brother-in-law, succeeded him when he died in 450 for a riding accident.