A.ruling the horse, epith. of Poseidon, Pi.P.4.45.
II. commander of cavalry, “τῆς ἵππου” Hdt.7.154; at Athens, IG22.116.15 (iv B.C.), Ar.Av.799, Lys.16.8, Pl.Lg.755c, 880d, X.Eq.Mag.1.7,al.; “ἵ. εἰς Λῆμνον χειροτονεῖν” Hyp.Lyc.17, cf. D. 4.26; in other states, Th.4.72, IG7.2466 (Thebes, iii B.C.), etc.; in the Achaean league, ib.5(2).344.7 (Orchomenus), etc.; = Lat. magister equitum, D.S.12.64, Plu.Cam.5, etc.; = praefectus equitum, App.Hisp.47; cf. ἱππάρχης.