Those beheaded included American journalist James Foley, another Israeli-American journalist Steven Sotloff, US aid worker David Haines, and Lebanese army sergeant Ali al-Sayyed.
A UN report in October 2014, based on nearly 500 interviews with witnesses, said Islamic State fighters took 450-500 women and girls to Iraq's Nineveh region in August, where, nearly 150 unmarried girls and women, mainly from Yazidi and Christian communities, were transported to Syria, either to be given to ISIS fighters as a reward or to be sold as sex slaves.
The same month, the UN confirmed that nearly 5,000 to 7,000 Yazidi women and children were abducted by IS fighters and sold into slavery.
Baghdadi's Islamic State justified enslaving Yazidi women in its digital magazine called Dabiq. The ISIS in late 2014 released a pamphlet saying its fighters are allowed to have sex with adolescent girls, and that it was acceptable to beat and trade them. "It is permissible to have sexual intercourse with the female captive", the pamphlet said.
Towards the end of the year, US and Allied nations began bombing installations run by the Islamic State, both in Syria and Iraq.
