Original sentence: The Islamist terrorist group Islamic State of Iraq and the Levant declared its governmental structure a 'caliphate' on June 29, 2014 after taking control of large swathes of territory in Syria (which for a prolonged period of time comprised over 50% of that country) and Iraq
Edited sentence: The Islamist group Islamic State of Iraq and the Levant declared its governmental structure a 'caliphate' on June 29, 2014 after taking control of large swathes of territory in Syria (which for a prolonged period of time comprised over 50% of that country) and Iraq