The Syrian Civil War is an armed conflict taking place in Syria. The unrest began in March 2011 with nationwide protests against president Bashar al-Assad's government, whose forces responded with violent crackdowns. The conflict gradually morphed from popular protests to an armed rebellion after months of military sieges. The armed opposition consists of various groups that were formed during the course of the conflict, including the Free Syrian Army and the Islamic Front. In 2013, Hezbollah entered the war in support of the Syrian army. In the east, the Islamic State of Iraq and the Levant (ISIS), a jihadist militant group which was initially linked to Al-Qaeda in Iraq, made rapid military gains in both Syria and Iraq, eventually turning against the rebels as well.