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.
Kingdom of Arles
In 1365, Charles was the last emperor to be crowned King of Arles. In 1378, Charles appointed the Dauphin of France (later King Charles VI of France) as permanent Imperial vicar to administer nominally on behalf of the Empire what remained of Arelat, and from then on Arelat in effect ceased to exist. However, the title "King of Arles" remained one of the Holy Roman Emperor's subsidiary titles until the dissolution of the Empire in 1806, and the office of the Archbishop of Trier continued to act as an archchancellor and prince-elector for the King of the Romans (the designated future Holy Roman Emperor), a status that was confirmed by the Golden Bull of 1356.