History of the Roman Empire
Theodosius was the last Emperor who ruled over the whole Empire. After his death in 395, he gave the two halves of the Empire to his two sons Arcadius and Honorius; Arcadius became ruler in the East, with his capital in Constantinople, and Honorius became ruler in the West, with his capital in Milan and later Ravenna. The Roman state would continue to have two different emperors with different seats of power throughout the 5th century, though the Eastern Romans considered themselves to be the only ones who were fully Roman. Latin was used in official writings as much as, if not more than, Greek and the two halves were nominally, culturally and historically, if not politically, the same state.
Roman triumph
For triumphs of the Roman regal era, the surviving Imperial "Fasti Triumphales" are incomplete. After three entries for the city's legendary founder Romulus, eleven lines of the list are missing. Next in sequence are Ancus Marcius, Tarquinius Priscus, Servius Tullius, and finally Tarquin "the proud", the last king. The "Fasti" were compiled some five centuries after the regal era, and probably represent an approved, official version of several different historical traditions. Likewise, the earliest surviving written histories of the regal era, written some centuries after it, attempt to reconcile various traditions, or else debate their merits. Dionysus, for example, gives Romulus three triumphs, the same number given in the "Fasti". Livy gives him none, and credits him instead with the first spolia opima, in which the arms and armour were stripped off a defeated foe, then dedicated to Jupiter. Plutarch gives him one, complete with chariot. Tarquin has two triumphs in the "Fasti" but none in Dionysius. No ancient source gives a triumph to Romulus' successor, the peaceful king Numa.