Augustus

Coin of the emperor Diocletian, marked diocletianus augustus Augustus (plural Augusti; /ɔːˈɡʌstəs/ aw-GUST-əs, Classical Latin: [au̯ˈɡʊstʊs]; "majestic", "great" or "venerable") was the main title of the Roman emperors during antiquity. It was given as both a name and a title to Gaius Julius Caesar Octavianus (often referred to simply as Augustus) in 27 BC, marking his accession as Rome's first emperor. On his death, it became an official title of his successor, and was so used by all emperors thereafter. The feminine form Augusta was used for Roman empresses and other female members of the imperial family. The masculine and feminine forms originated in the time of the Roman Republic, in connection with things considered divine or sacred in traditional Roman religion. Their use as titles for major and minor Roman deities of the Empire associated the imperial system and family with traditional Roman virtues and the divine will and may be considered a feature of the Roman imperial cult.

In Rome's Greek-speaking provinces, "Augustus" was translated as Sebastos (Σεβαστός), or Hellenised as Augoustos (Αὔγουστος); these titles continued to be used in the Byzantine Empire until the Fall of Constantinople in 1453, although they gradually lost their imperial exclusivity in favour of Basileus and Autokrator.