Roman III was a ruler of the Roman Empire from AD 383 to AD 408. He was the son of Theodosius I and was the last emperor of the Theodosian dynasty. He was known for his military campaigns against the Visigoths, which resulted in the capture of Rome in 410. He also issued several edicts that strengthened the Christian faith in the empire. His reign was marked by a period of relative peace and prosperity. TRE is an abbreviation for the Latin phrase 'Tres Romani Imperatori', meaning 'three Roman emperors'.