
Though the Empire had seen periods with more than one emperor ruling jointly before, the view that it was impossible for a single emperor to govern the entire Empire was institutionalised with reforms to Roman law by emperor Diocletian following the disastrous civil wars and disintegrations of the Crisis of the Third Century. The Western Roman Empire collapsed in 476, and the Western imperial court in Ravenna was formally dissolved by Justinian I in 554 AD. The terms Western Roman Empire and Eastern Roman Empire were coined in modern times to describe political entities that were de facto independent contemporary Romans did not consider the Empire to have been split into two empires but viewed it as a single polity governed by two imperial courts for administrative expediency. Particularly during the period from 395 to 476 AD, there were separate, coequal courts dividing the governance of the empire into the Western provinces and the Eastern provinces with a distinct imperial succession in the separate courts. The term Western Roman Empire is used in modern historiography to refer to the western provinces of the Roman Empire, collectively, during any period in which they were administered separately from the eastern provinces by a separate, independent Imperial court. ^ The de jure last emperor, Julius Nepos, reigned for five years in exile from Salona/Spalatum in Dalmatia.Another suggested end date is the reorganization of the Italian peninsula and abolition of separate Western Roman administrative institutions under Emperor Justinian during the latter half of the 6th century. ^ Whilst the deposition of Emperor Romulus Augustulus in 476 AD is the most commonly cited end date for the Western Roman Empire, the last Western Roman emperor Julius Nepos, was assassinated in 480, when the title and notion of a separate Western Empire were abolished.In the ancient era the Latin term often used was " S.P.Q.R." ("Senatus Populusque Romanus" Latin) used in documents, on flags and banners and carved/engraved on buildings. Terms such as Imperium Romanum Occidentale and Hesperium Imperium were either never in official usage or invented by later medieval or modern historians long after the Western Roman court had fallen. ^ Since the Western Roman Empire was not a distinct state separate from the Eastern Roman Empire, there was no particular official term that designated the Western provinces or their government, which was simply known at the time as the "Roman Empire".
