[43][71][72][73] The operation, which was called Operation "We Are Coming, Nineveh" (قادمون يا نينوى; Qadimun Ya Naynawa),[74][75] began on 16 October 2016, with forces besieging ISIL-controlled areas in the Nineveh Governorate surrounding Mosul,[76][77][78] and continued with Iraqi troops and Peshmerga fighters engaging ISIL on three fronts outside Mosul, going from village to village in the surrounding area in the largest deployment of Iraqi troops since the 2003 invasion of Iraq.

[80] Met with fierce fighting, the government advance into the city was slowed by elaborate defenses and by the presence of civilians,[81] but the Iraqi Prime Minister Haider al-Abadi declared "full liberation of eastern side of Mosul" on 24 January 2017.

The city was once extremely diverse, with ethnic minorities including Armenians, Yazidis, Assyrian, Turkmen and Shabak people, all of whom have suffered under the (majority Sunni Arab) Islamic State.

[79] Royal Air Force's Reaper drones, Typhoons, and Tornados targeted "rocket launchers, ammunition stockpiles, artillery pieces and mortar positions" in the 72 hours before the ground assault began.

[117] About 560 U.S. troops from the 101st Airborne Division were deployed to Q-West for the battle, including command and control elements, a security detachment, an airfield operations team, and logistics and communications specialists.

[132] On the southern front, Iraqi troops retook several villages near Qayyarah, including al-Sirt, Bajwaniya, al-Hud and al-Mashraf, and parts of the al-Hamdaniya District southeast of Mosul.

[135] Iraqi Army forces stormed Qaraqosh (Bakhdida), once the largest Assyrian town in Iraq, and fought with ISIL fighters who remained holed up, while also Hammam al-'Alil.

The allied forces began their assault in Mosul's eastern Karama district, with artillery, tank and machine-gun fire on ISIL positions as they prepared the larger push into the city.

[80] Heavy fighting occurred in the Gogjali district, at the gate of the entrance to eastern Mosul, where ISIL militants used car bombs and sniper fire to try to halt the advance.

[212] On 6 November, Iraqi forces in the southwestern front stated that they were 4 kilometres (2.5 mi) from Mosul International Airport, after taking control of Hamam al-Alil on the previous day.

[252] On 16 December, the PMF captured the Tel Abtah district, home to almost 50,000 people and a major strategic ISIL stronghold, and advanced on more villages to the south and southwest of Tal Afar.

[254] On 19 December, Iraqi forces stormed into the al-Mazare' area, after retaking large parts of al-Wahda in southeastern Mosul, and also killed 14 ISIL fighters, including four suicide bombers.

[260] On 26 December, Commander of Nineveh Operations Major General Najim al-Jabouri announced that new military reinforcements had arrived in the Mosul neighborhoods retaken by Iraqi forces.

[277] Iraqi Air Force airstrikes destroyed the office of ISIL's hisbah police located on Mosul-Tel Afar road, and several warfare utilities of the group.

General Raed Shaker Jawdat stated that the group's headquarters in Nineveh province had been destroyed and that Iraqi forces had captured eight districts in the second phase, thus bringing the entire southeastern section of Mosul under their control.

[332] On 19 January, the Iraqi Army captured the town of Tel Kayf, to the north of Mosul (after a nearly three-month-long siege),[333][334] as well as the Nineveh Oberoi hotel and the "Palaces" area on the eastern bank of the Tigris.

[350] Airstrikes by the anti-ISIL coalition killed Haqi Ismail Hamid al-Emri, a former member of al-Qaeda in Iraq who played a leadership role of ISIL's security networks in Mosul.

[354] Meanwhile, many news outlets reported the end of the battle during the mid-to-late-July period, with the focus of Iraqi forces now being hunting down surviving militants, clearing explosives and dead bodies.

[358] The Sudan Tribune reported on 5 August that Ali Abdel-Ma'arouf (aka Abu al-Asbat Al-Sudani), a Sudanese national, who was ISIL head of prisons and a top legislator, was killed during recent clearing operations in Mosul.

[359] On 8 August, a security source said that ISF in coordination with the Nineveh police, had arrested Ahmed Sabhan Abdel Wahid al-Dulaimi, a senior ISIL intelligence official, in east Mosul.

[365] Lieutenant-Colonel Abdul Salam al-Jabouri said on 12 October that some ISIL terrorists who had survived the military offensive in Mosul were detected in the marshlands area alongside near the Tigris, after they sent threats to some Tribal Mobilization leaders via SMS.

[78][389] On 21 October, International Business Times reported that "disturbing and graphic footage posted to social media allegedly shows Iraqi security forces torturing and interrogating young children for information about ISIL as they attempt to retake Mosul from the Islamic State terror group.

The WHO said that they had enabled "an emergency response plan to safely treat men, women and children who may be exposed to the highly toxic chemical[s]" and were preparing for more patients with exposure to these agents.

[400] The World Health Organization (WHO) said it had trained 90 Iraqi medics in "mass casualty management" as part of its preparations for the Mosul operation, with a special focus on responding to chemical attacks, AP reported.

[56] The following day, WHO announced it had established 82 "rapid response teams" to prepare for possible concerns among civilians fleeing Mosul, including health epidemics such as cholera, and exposure to chemicals and smoke from burning oil wells.

[408] Iraqi Baath Party Several media outlets including Al Jazeera and Channel 4 live streamed the first day's battle on Facebook, a first in war coverage.

[423] Brendan Gauthier, assistant editor of Salon, noted that given ISIL's slick campaigns on social media, "It's only appropriate then that the Iraqi military's effort to reclaim Mosul from the PR machine turned extremist group be live-streamed.

"[425] Journalist Mustafa Habib reported that Iraqi citizens are coordinating efforts on Facebook and Twitter to counter ISIL propaganda, such as fake photos and videos, that may be used to intimidate locals in Mosul.

Previously, they occupied other clinics in other towns controlled by the Islamic State fighters in Iraq, as well operating offices in all the medical facilities in the Republican, Ibn Sina, al-Salam, and Mosul General Hospitals.

[444] According to a report published by UN Assistance Mission for Iraq and the Office of the UN High Commissioner for Human Rights in November 2017, at least 2,521 civilians were killed in the battle, mostly because of ISIL including executions of at least 741.