The Qollar-aghasi, also spelled Qullar-aqasi, was the commander of the Safavid Empire's élite gholam (also spelled ghulam) corps. The word means lord of slaves in Azeri (qullar means 'slaves' and ağası means 'lord of'). The holder of the office was one of the most powerful individuals in the entire Safavid state, and in fact by the end of the Safavid-era, he was the most important military official after the qurchi-bashi.