The merarchēs (Greek: μεράρχης), sometimes Anglicized as merarch, was a Byzantine military rank roughly equivalent to a divisional general.
[2][4][5][6] This division was maintained in the later Byzantine army, although already from the 7th century, the term merarchēs became used less frequently, being dropped in favour of tourmarchēs; likewise, the tourma replaced the meros both in technical and common parlance.
[9] Since the merarchēs – also found in the corrupted form meriarchēs (Greek: μεριάρχης) – is sometimes distinguished in the sources (e.g. the Klētorologion of Philotheos) from the other tourmarchai, the scholar John B.
Bury suggested that in the 9th and 10th centuries, the merarchēs was a distinct post, held by the tourmarchēs attached as an aide and deputy to the thematic stratēgos with no geographical area under his command, as opposed to the two "regular" tourmarchai.
[4] The discovery of a seal of a merarchēs of Knossos shows that they did hold territorial assignments, leading Alexander Kazhdan to reject Bury's hypothesis in the Oxford Dictionary of Byzantium.