Theodosius II, called "the Calligrapher", was Roman emperor from 402 to 450. He was proclaimed Augustus as an infant and ruled as the Eastern Empire's sole emperor after the death of his father Arcadius in 408. His reign was marked by the promulgation of the Theodosian law code, the construction of the Theodosian walls of Constantinople, and the founding of the oldest university in the world, University of Constantinople. He also presided over the outbreak of two great Christological controversies, Nestorianism and Eutychianism.