A.tetrarchy, the province of a tetrarch, esp. of Thessaly, the four provinces being Thessaliotis, Phthiotis, Pelasgiotis, Hestiaeotis, Hellanic. 52J., E Alc.1154, D.9.26, Theopomp.Hist.201; also of the four divisions of each of the three Galatian tribes, Str.12.5.1; ἡ τῶν δώδεκα τ. βουλή v.l. ibid.; cf. “τετράς” 11.
2. generally, of the divisions of Roman protectorates, e.g. Palestine under Augustus, J.BJ2.6.3; districts adjacent to Syria, tetrarchiae regnorum instar singulae, Plin.HN5.74.
II. τ. ἱππική the command of four λόχοι, Arr.An. 3.18.5, cf. Id.Tact.10.1, Ael.Tact.9.2, Ascl.Tact.2.8; Φιλίππου τετραρχίας ἔργον monument erected by Philip's τ., IG9(1).316 (Scarphea, Locr. Orient., iv B.C.).