The Pentagon confirmed Thursday night that the U.S. was responsible for killing one of the most powerful military figures in Iran and across the Middle East.

The death of its target, Maj. Gen. Qassem Soleimani of Iran , marks an extreme escalation in U.S.-Iran hostilities and nearly guarantees an act of revenge from Iran.

Heres what you need to know about the top Iranian commander and why his death is a game-changer for the Middle East.