Theodosius II (Greek: Θεοδόσιος Theodosios; 10 April 401 – 28 July 450), commonly called Theodosius the Younger, was Roman emperor for most of his life, proclaimed Augustus as an infant in 402 and ruling 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 and the construction of the Theodosian Walls of Constantinople. He also presided over the outbreak of two great Christological controversies, Nestorianism and Eutychianism.