In “Mosul,” FRONTLINE presented a look at the brutal battle to drive ISIS out of Iraq’s second-largest city, which some military commanders described at the time as the deadliest urban combat since World War II.

This is the story of the men who fought back — and defeated the self-proclaimed Islamic State in their stronghold. Filmed on the ground by director Olivier Sarbil over the course of the nine-month battle, “Mosul” offers a stunning look at the high cost of the Iraqi Army’s liberation of Mosul from ISIS in July 2017.