This chapter examines the emergence of sectarianism in Iraq. Sectarian identities have long persisted in Iraq. And although they tend to cause violence, sectarian violence did not persist as a social constant; rather, outbreaks of sectarian violence only happened on specific occasions. For some observers, Iraq is divided into three distinct ethno-sectarian regions: the Shi’i Arab in southern Iraq, the Sunni Arab in central Iraq, and the Sunni Kurdish in northern Iraq. These geographic divisions are seen within the tripartite ‘no-fly zone’ borders of 1991 to 2003. While this portrayal does bear some resemblance to reality, it is insufficient in defining Iraqi society. However in the wake of the 2003 Anglo-American invasion, the occupation authorities formed policies which encouraged gradual, progressive and incessant increases in social chaos and a sectarianism that eventually led to the violent geographic consolidation of Iraq’s ethno-sectarianism mapping.