The
Western Roman Empire refers to the western half of the
Roman Empire, from its division by
Diocletian in 285; the other half of the Roman Empire was the Eastern Roman Empire, today widely known as the
Byzantine Empire.
The Western Empire existed intermittently in several periods between the 3rd century and 5th century, after Diocletian's Tetrarchy and the reunifications associated with Constantine the Great and Julian the Apostate (324-363). Theodosius I (379-395) was the last Roman Emperor who ruled over a unified Roman empire. After his death in 395, the Roman Empire was permanently divided. The Western Roman Empire ended officially with the abdication of Romulus Augustus under pressure of Odoacer on 4 September 476, and unofficially with the death of Julius Nepos in 480.
Despite a brief period of reconquest by its counterpart, the Eastern Roman Empire, the Western Roman Empire would not rise again. As the Western Roman Empire fell, a new era began in Western European history the Middle Ages and more specifically the Dark Ages.
As the Roman Republic expanded, it reached a point at which the central government in Rome could not effectively rule the distant provinces. Communications and transportation were especially problematic, given the vast extent of the Empire. News of invasion, revolt, natural disaster, or epidemic outbreak was carried by ship or mounted postal service, often requiring much time to reach Rome, and for Rome's orders to be realized in the province of origin. For this reason, provincial governors had de facto rule in the name of the Roman republic.
