<P> Due to the cultural rupture of the Turkish conquest, most western historians treat Constantine XI as the last meaningful claimant to the title Roman Emperor, although from 1453 Ottoman rulers were titled "Caesar of Rome" (Turkish: Kayser - i Rum) until the Ottoman Empire ended in 1922 . A Byzantine group of claimant Roman Emperors existed in the Empire of Trebizond until its conquest by the Ottomans in 1461 . In western Europe the title of Roman Emperor was revived by Germanic rulers, the "Holy Roman Emperors", in 800, and was used until 1806 . </P> <P> Modern historians conventionally regard Augustus as the first Emperor whereas Julius Caesar is considered the last dictator of the Roman Republic, a view having its origins in the Roman writers Plutarch, Tacitus and Cassius Dio . However, the majority of Roman writers, including Josephus, Pliny the Younger, Suetonius and Appian, as well as most of the ordinary people of the Empire, thought of Julius Caesar as the first Emperor . </P> <P> At the end of the Roman Republic no new, and certainly no single, title indicated the individual who held supreme power . Insofar as emperor could be seen as the English translation of imperator, then Julius Caesar had been an emperor, like several Roman generals before him . Instead, by the end of the civil wars in which Julius Caesar had led his armies, it became clear that there was certainly no consensus to return to the old - style monarchy, but that the period when several officials, bestowed with equal power by the senate, would fight one another had come to an end . </P> <P> Julius Caesar, and then Augustus after him, accumulated offices and titles of the highest importance in the Republic, making the power attached to those offices permanent, and preventing anyone with similar aspirations from accumulating or maintaining power for themselves . However, Julius Caesar, unlike those after him, did so without the Senate's vote and approval . </P>

The administrative organization of the roman empire can be said to be in what medieval institution