Augustus, considered the first Roman emperor, established his hegemony by collecting on himself offices, titles, and honours of Republican Rome that had traditionally been distributed to different people, concentrating what had been distributed power in one man. One of these offices was princeps senatus, ("first man of the Senate") and became changed into Augustus' chief honorific, princeps civitatis ("first citizen") from which the modern English word and title prince is descended. The first period of the Roman Empire, from 27 BC to AD 284, is called the principate for this reason. However, it was the informal descriptive of Imperator ("commander") that became the title increasingly favored by his successors. Previously bestowed on high officials and military commanders who had imperium, Augustus reserved it exclusively to himself as the ultimate holder of all imperium. (Imperium is Latin for the authority to command, one of a various types of authority delineated in Roman political thought.)