'autokrator' originates from Ancient Greek, specifically the word 'αὐτοκράτωρ' (autokrátōr), where 'αὐτ-' (aut-) meant 'self' and 'κράτος' (kratos) meant 'power' or 'rule'.

'autokrator' passed from Ancient Greek 'αὐτοκράτωρ' into Byzantine/Medieval Greek as 'αὐτοκράτωρ' and was used as a formal title for the Byzantine emperor; the element and concept later entered Latin as 'autocrator' and thence into scholarly and historical English usage (parallel to the development of the related modern word 'autocrat').

Initially it meant 'one who rules by (his) own power' or 'self-ruler' (often as a military or supreme commander), but over time it became a formal imperial title in Byzantium and was later generalized in modern languages to mean 'autocrat' or 'absolute ruler'.