1) Byzantine military office 2) Military rank of Greece 
Chiliarch (from χιλίαρχος, chiliarchos, sometimes χιλιάρχης, chiliarches or χειλίαρχος, cheiliarchos; meaning `commander of a thousand`) is a military rank dating back to Antiquity. The command of a chiliarch is called a chiliarchy (χιλιαρχία, chiliarchia). == Ancient Greece == In the Ancient Macedonian army,.....
• (n.) The commander or chief of a thousand men.
originally, the commander of a thousand in the armed muster of a Russian town; later, an important official, especially in Novgorod and towns with a similar constitution.
chiliarch The commander of a thousand men; properly a term of Greek or Roman history.
(in ancient Greece) the military commander of 1000 men.