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.
Justinian II
Justinian II (, "Ioustinianos II"; ; 668 – 11 December 711), surnamed the Rhinotmetos or Rhinotmetus (, "the slit-nosed"), was the last Byzantine Emperor of the , reigning from 685 to 695 and again from 705 to 711. Justinian II was an ambitious and passionate ruler who was keen to restore the Roman Empire to its former glories, but he responded poorly to any opposition to his will and lacked the finesse of his father, Constantine IV. Consequently, he generated enormous opposition to his reign, resulting in his deposition in 695 in a popular uprising, and he only returned to the throne in 705 with the help of a Bulgar and Slav army. His second reign was even more despotic than the first, and it too saw his eventual overthrow in 711, abandoned by his army who turned on him before killing him.