More than 140,000 people have been killed in the war that began in March 2011 as an uprising against Assad's government. It since has largely divided along sectarian lines, with a chaotic mix of mostly Sunni rebels pitted against Syria's minorities, including Christians, Shiites and Alawites, who largely have sided with the government or remained neutral. Assad himself is part of the Alawite sect, an offshoot of Shiite Islam.