The Siege of Kobani was a major battle of the Syrian Civil War that was fought from September 2014 to March 2015 as the Islamic State besieged the major Syrian-Kurdish city of Kobani on the Turkish border.
The Kurdish YPG had captured Kobani on 19 July 2012, after which the Kurds established the autonomous region of Rojava in northeastern Syria. In August 2013, the Islamic State of Iraq and the Levant, the al-Nusra Front, Ahrar ash-Sham, the Suqour al-Sham Brigade, and the al-Tawhid Brigade announced that they would besiege Kobani, but infighting between the Islamist groups erupted in January 2014, and some of them formed the pro-YPG Euphrates Islamic Liberation Front. In March 2014, ISIL captured Sarrin and several other towns and villages from the YPG and EILF, and ISIL began to attack Kobani and its surrounding villages in July 2014.
On 15 September 2014, ISIL launched a massive offensive to capture the Kobani Canton, using tanks, rockets, and artillery to capture 21 villages within 24 hours. Kobani was encircled by ISIL forces, and the remaining Free Syrian Army units in the area were forced to retreat into Kobani itself. By 2 October, ISIL captured 350 Kurdish villages in the vicinity of Kobani, forcing up to 400,000 Kurdish refugees to flee across the Turkish border.
As ISIL threatened to capture Kobani, the Kurdistan Workers' Party (PKK) and Turkish communist groups such as the MLKP, TKP/ML, United Freedom Forces, and People's Liberation Faction began to send volunteers to aid in the city's defense. On 27 September, US-led coalition planes began to bomb ISIL frontline positions, despite an earlier hesitation caused by Turkey's preference for a Kurdish defeat. Into early October, ISIL continued to advance, entering the suburbs of Kobani and perpetrating war crimes such as torture, rape, murder, and mutilation; female YPJ fighters were among the Kurdish soldiers beheaded by ISIL.
On 5 October, ISIL militants began to enter Kobani itself, breaking through Kurdish defenses and using Mistanour Hill to set up sniper and heavy machine-gun positions. By 6 October, ISIL had 9,000 militants in the Kobani Canton. Heavy fighting ensued, and the Kurds were able to expel ISIL fighters from much of eastern Kobani as US airstrikes destroyed a tank, three technichals, and an ISIL unit. By 9 October, ISIL was in control of more than a third of the city, utilizing suicide bombings to assault the city. On 11 October, even after taking the Kurdish command center in Kobani and half of the city, ISIL failed to capture the city center. The Kurds desperately fought off ISIL attempts to capture the Turkish border crossing, their only avenue of reinforcement, and the Americans began to coordinate with the Kurds, who would provide them with targets for their airstrikes. Several ISIL attempts to capture the border gate with Turkey failed, and Free Syrian Army reinforcements began to arrive from Turkey on 29 October. On 5 November, Iraqi Kurdistan began to send several truckloads of ammunition to Kobani via Turkey, and Peshmerga reinforcements helped the YPG to inflict hundreds of losses on ISIL. The Kurds began to recapture lost territory, and, from 26 to 27 January, Kurdish forces rapidly recaptured the city from ISIL forces. Most of the remaining villages in the canton remained under ISIL control, but the YPG and its allies made rapid advances in rural Kobani and cleared the canton by late April 2015. A new ISIL offensive in June 2015 resulted in the Kobani massacre, during which 233 civilians were killed, but ISIL was quickly driven back.
The Siege of Kobani was considered a turning point in the war against the Islamic State, as the "Kurdish Stalingrad" - 70% of which was destroyed by the fighting - was the high water mark of ISIL's advance into Rojava, and the Kurdish-Coalition partnership eventually resulted in the defeat of ISIL in Syria.