Fall of Mosul

Battle context

The fall of Mosul between 4 and 10 June 2014 marked a decisive turning point in the Iraqi Civil War of 2014–2017. A force of between 1,500 and 5,500 ISIL fighters and allied insurgents seized Iraq's second-largest city from an Iraqi Army garrison nominally numbering 60,000 troops — a collapse that exposed catastrophic failures in Iraqi military cohesion and command under Lieutenant General Mahdi al-Gharrawi. Iraqi casualties reached 4,000, and the city fell within days. The speed and scale of the defeat fundamentally altered the strategic landscape of the conflict: ISIL's capture of Mosul provided the group with a major urban base, vast materiel abandoned by fleeing Iraqi forces, and the territorial foundation from which its self-declared caliphate would be proclaimed days later. The battle demonstrated that the Iraqi security apparatus, as then constituted, could not hold northern Iraq against a determined insurgent offensive, triggering an international response and reshaping the entire trajectory of the war.