chiliarch

noun

1. (historical)A commander of a thousand troops in Hellenistic Greece.

   “And Dadaces, the chiliarch, spear-struck, Forth from his galley leapt with nimble bound.”

   “When I had seen it, I halted and turned to look up at the peak on whose slope we walked. I could see the face now and its mitre of ice, and below it the left shoulder, where a thousand cavalrymen might have been exercised by their chiliarch.”