The interest of this paper lies in the distinction between θεoτόкoς (‘Theotokos’), ‘God-bearer’, and words or phrases which are more precisely translated as ‘mother of God’, especially μήτηρ θεoυ̂ (‘mētēr theou’) and θεoμήτωρ (‘theomētōr’) in Greek and mater Dei in Latin. It concentrates on the usage of Greek and Latin Christian writers between the later fourth century and the eighth century. For those who believe that ‘mother of God’ is the only proper rendering in English of θεoτόкoς, it must seem a non-issue. Indeed, insofar as they have most of the tradition on their side, this enquiry may appear redundant, impertinent, or sectarian. To leave the matter there, however, would be to leave important questions unasked. Historical study is not best served by the indiscriminate translation of θεoτόкoς as ‘mother of God’, or at least by a translation that fails clearly to distinguish between θεoτόкoς and direct equivalents of ‘mother of God’.