The Siege of Mosul (also Battle of Mosul) was an offensive carried out by Kurdish and Iraqi forces and local militia with US Air Support.
In January 2014 ISIL annexed Fallujah and Ramadi, and on June 4th they moved toward Mosul. While the Iraqi Government had 30,000 soldiers and ISIL just 1500, after six days of fighting the city and surrounding area, including Mosul International Airport and many helicopters, were under ISIL control, with hundreds of thousands of civilians and soldiers retreating.
For the next two years, Mosul was to be within the oppressive forces of ISIL.
Since the creation of an Independent Kurdistan, ISIL had been losing much land. However, on the 8th March 2016, the Peshmerga, using Russian equipment, such as T-72s and 2A65-Msta-Bs, launched a major assault and retook Tal Afar from ISIL. By the 9th they had secured offensive positions around the city, and on the 10th they besieged the city. On the 14th, major gains were made by the Peshmerga, pushing ISIL forces to the centre of the city. By the beginning of April Da'esh forces had been completely pushed out of the city, concluding the siege and offensive.