A History of the Islamic State Group's Atrocities as Iraq Claims Victory Over it in Tikrit

The extremist Islamic State group, which controls a third of both Iraq and Syria in its self-declared caliphate, found itself driven out of the city of Tikrit on Wednesday by an allied Iraqi force backed by U.S.-led airstrikes.
The monthlong offensive to retake Tikrit, the hometown of Saddam Hussein some 80 miles north of Baghdad, is the biggest victory yet for Iraq since the extremists' campaign last summer. However, the Islamic State group remains a potent threat, Western officials warn.