The Islamic State (ISIS) rose to prominence in 2014, seizing control of territory in Iraq and Syria.
Emerging from the remnants of Al Qaeda, it faded into obscurity after the surge of US troops to Iraq.
However, it began to reemerge, taking advantage of growing instability in Iraq and Syria.
ISIS launched an offensive on Mosul and Tikrit in June 2014.
By 2015, despite US airstrikes of up to 8,000, ISIS expanded into a network of affiliates in at least eight other countries.
There, they would carry out coordinated attacks through the use of bombs and/or guns, as well as other excessively violent acts.
This period was very lucrative for ISIS. Its power had emerged largely based around unpredictable asymmetric warfare and its ability to dispersequickly when under attack.
When ISIS was operating as a quasi-state, power was ultimately challenged because ISIS was attacked by conventionalmilitary forces and because it was centred around Mosul and Raqqa, it was forced into a fixed location