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.
Persecution of pagans in the late Roman Empire
In 476, the last western emperor, Romulus Augustulus, was deposed by Odoacer, who became the first "barbarian" king of Italy. Pagans used the occasion to attempt to revive the old rites. In 484, the Magister militum per Orientem, Illus, revolted against Eastern Emperor Zeno and raised his own candidate, Leontius, to the throne. Leontius hoped to reopen the temples and restore the ancient ceremonies; as such, many Pagans joined in his revolt against Zeno. Illus and Leontius were compelled, however, to flee to a remote Isaurian fortress, where Zeno besieged them for four years. Zeno finally captured them in 488 and promptly had them executed. Following the revolt, Zeno instituted harsh anti-paganism policies. With the failure of the revolt of Leontios, some pagans became disillusioned and became Christian, or pretended to do so, in order to avoid persecution. The subjugation of the Roman Empire to Christianity became complete when the emperor Anastasius I, who came to the throne in 491, was required to sign a written declaration of orthodoxy before his coronation.