On September 15, 2014, the Islamic State of Iraq and the Levant launched the Siege of Kobanî, the culmination of a year-long offensive into northern Syria. But by late January 2015, the YPG-led forces recapture the city, driving ISIL back. Some of the defenders of Kobanî were made up by international volunteers of the United Freedom Forces, including the Turkish green anarchist group Social Insurrection, which had been founded in Tuzluçayır in 2013. The internationalist participation in the battle for Kobanî inspired the formation of the International Freedom Battalion (IFB), which united left-wing foreign fighters in support of the Autonomous Administration.