Plato, Laws 756a

τὴν ἀσπίδα τιθέμενοι, φυλάρχους δὲ αὖ τούτοις πᾶν τὸ ἱππικὸν αἱρείσθω, ψιλῶν δὲ ἢ τοξοτῶν ἤ τινος ἄλλου τῶν ἐμπολεμίων ἡγεμόνας οἱ στρατηγοὶ ἑαυτοῖς καθιστάντων. ἱππάρχων δὴ κατάστασις ἂν ἡμῖν ἔτι λοιπὴ γίγνοιτο. τούτους οὖν προβαλλέσθων μὲν οἵπερ καὶ τοὺς στρατηγοὺς προυβάλλοντο, τὴν δὲ αἵρεσιν καὶ τὴν ἀντιπροβολὴν τούτων τὴν αὐτὴν γίγνεσθαι καθάπερ ἡ τῶν στρατηγῶν ἐγίγνετο,

all the cavalry shall elect for themselves phylarchs; the commanders shall appoint for themselves captains of skirmishers, archers, or any other branch of service. The appointment of hipparchs we have still remaining. They shall be nominated by the same persons who nominated the commanders, and the mode of selection and counter-nomination shall be the same in their case as in that of the commanders: the cavalry shall vote for them