The hetaireiarches (‹See Tfd›Greek: ἑταιρειάρχης), sometimes anglicized as Hetaeriarch, was a high-ranking Byzantine officer, in command of the imperial bodyguard, the Hetaireia. In the 9th–10th centuries there appear to have been several hetaireiarchai, each for one of the subdivisions of the Hetaireia, but in later times only the senior of them, the megas hetaireiarches (‹See Tfd›Greek: μέγας ἑταιρειάρχης) or Great Hetaeriarch survived, eventually becoming simply a high court rank in the 12th–15th centuries.