1) Byzantine military office 2) Military rank of Greece 
Taxiarch, the anglicized form of taxiarchos or taxiarchēs (ταξίαρχος or ταξιάρχης) is used in the Greek language to mean `brigadier`. The term derives from táxis, `order`, in military context `an ordered formation`. In turn, the rank has given rise to the Greek term for brigade, taxiarchia. In Greek Orthodox Church usage,...
officer.
• (n.) An Athenian military officer commanding a certain division of an army.
Tax'i·arch noun [ Greek ... and ...; ... a division of an army, a brigade (from ... to arrange, array) + to rule.] (Gr. Antiq.) An Athenian military officer commanding a certain division of an army. Milford.