Theodosius II was Roman emperor from 402 to 450. Proclaimed augustus as an infant, he ruled as the eastern Empire's sole emperor after the death of his father, Arcadius, in 408. Also known as Theodosius the Calligrapher he is famous for developing the Codex Theososianus, or the Theodosian law code, an important compilation of Roman law. He also founded the University of Constantinople and ordered the construction of the Theodosian Walls that defended that city's western front. Theodosius II also presided over the outbreak of two great Christological controversies, Nestorianism and Eutychianism.