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.
History of Italy
In 27 BC, Augustus established the Roman Empire and inaugurated the Pax Romana, two centuries of stability and relative peace in which Italy flourished as the leading political and economic centre of the "known world". The death of the last of the "good emperors", Marcus Aurelius, and the crisis of the third century marked the beginning of the decline of Rome. The Empire went through major changes in the following centuries, including a division between West and East in 286 under Diocletian and the end of the persecutions of Christians with the Edict of Milan of 313 under Constantine. The Bishop of Rome was granted religious primacy with the Edict of Thessalonica in 380 and the West collapsed amid barbarian invasions in 476, when Odoacer deposed Romulus Augustus.