When was the Roman Republic formed?
Roman Republic
The Roman Republic (Latin: Rēs pūblica Rōmāna, Classical Latin:[ˈreːs ˈpuːb.lɪ.ka roːˈmaː.na]; Italian: Repubblica romana) was the era of classical Roman civilization beginning with the overthrow of the Roman Kingdom, traditionally dated to 509 BC, and ending in 27 BC with the establishment of the Roman Empire. It was during this period that Rome's control expanded from the city's immediate surroundings to hegemony over the entire Mediterranean world.
Western Roman Empire
In 476, after the Battle of Ravenna, the Roman Army in the West suffered defeat at the hands of Odoacer and his Germanic "foederati". Odoacer forced the deposition of emperor Romulus Augustulus and became the first King of Italy. In 480, following the assassination of the previous Western emperor Julius Nepos, the Eastern emperor Zeno dissolved the Western court and proclaimed himself the sole emperor of the Roman Empire. The date of 476 was popularized by the 18th century British historian Edward Gibbon as a demarcating event for the end of the Western Empire and is sometimes used to mark the transition from Antiquity to the Middle Ages. Odoacer's Italy, and other barbarian kingdoms, would maintain a pretence of Roman continuity through the continued use of the old Roman administrative systems and nominal subservience to the Eastern Roman court.