Roman Emperors and Empresses were rulers of the
Roman Empire, wielding power over its citizens and military. The empire was developed as the
Roman Republic invaded and occupied most of Europe and portions of northern Africa and western Asia. Under the republic, regions of the empire were ruled by provincial governors answerable to and authorised by the "
Senate and People of Rome". Rome and its senate were ruled by a variety of magistrates – of whom the
consuls were the most powerful. The republic ended, and the emperors were created, when these magistrates became legally and practically subservient to one citizen with power over all other magistrates.
Augustus, the first emperor, was careful to maintain the facade of republican rule, taking no specific title for his position and calling the concentration of magisterial power
Princeps Senatus (the first man of the senate). This style of government lasted for 300 years, and is thus called the
Principate era. The modern word 'emperor' derives from the title
imperator, which was granted by an army to a successful general; during the initial phase of the empire, it still had to be earned by the 'Princeps'. The term emperor is a modern construction, used when describing rulers of the Roman Empire because it emphasises the strong links between the ruler and the army (on whose support the ruler's power depended), and does not discriminate between the personal styles of rule and titles in different phases of the Empire.