CONSTANTIUS III. was born in Illyria in the second half of the 4th century A.D. He fought for Honorius against Gerontius in Gaul and Spain, reduced Arles and captured Constantine the Tyrant. He was consul in 414, defeated Ataulphus and married Placidia, the sister of Honorius. In 421 he was named Augustus and co-emperor of the West, and he died at Ravenna in September of that year.
See Zosimus v. and vi.