Roman emperor
The Western Roman Empire collapsed in the late 5th century. Romulus Augustulus is often considered to be the last emperor of the West after his forced abdication in 476, although Julius Nepos maintained a claim recognized by the Eastern Empire to the title until his death in 480. Following Nepos' death, the Eastern Emperor Zeno abolished the division of the position and proclaimed himself as the sole Emperor of a reunited Roman Empire. The Eastern imperial lineage continued to rule from Constantinople ("New Rome"); they continued to style themselves as Emperor of the Romans (later βασιλεύς Ῥωμαίων in Greek), but are often referred to in modern scholarship as Byzantine emperors. Constantine XI Palaiologos was the last Roman emperor in Constantinople, dying in the Fall of Constantinople to the Ottomans in 1453.
Ostrogothic Kingdom
In Italy the Ostrogoths, led by Theoderic the Great, killed and replaced Odoacer, a Germanic soldier, erstwhile-leader of the "foederati" in Northern Italy, and the "de facto" ruler of Italy, who had deposed the last emperor of the Western Roman Empire, Romulus Augustulus, in 476. Under Theoderic, its first king, the Ostrogothic kingdom reached its zenith, stretching from modern France in the west into modern Serbia in the southeast. Most of the social institutions of the late Western Roman Empire were preserved during his rule. Theodoric called himself "Gothorum Romanorumque rex" ("King of the Goths and Romans"), demonstrating his desire to be a leader for both peoples.