Originating as the "Jama'at al-Tawhid wal-Jihad" in 1999, ISIL pledged allegiance to al-Qaeda in 2004, participated in the Iraqi insurgency that followed the invasion of Iraq by Western coalition forces in 2003, joined the fight in the Syrian Civil War beginning in 2011, and was expelled from al-Qaeda in early 2014, (which complained of its failure to consult and "notorious intransigence"). ISIL gained prominence after it drove Iraqi government forces out of key cities in western Iraq in an offensive in June that same year. The group is adept at social media, posting Internet videos of beheadings of soldiers, civilians, journalists and aid workers, and is known for its destruction of cultural heritage sites.