Baghdad’s religious make-up has historically been contested between Sunni and Shia Muslims, however the 2003 invasion by the US and its allies provided the backdrop for a sharp rise in sectarian violence. This violence fully erupted in 2006 following the 22 February bombing of the al-Askari mosque in Samarra, one of Shia Islam’s holiest sites, which caused outrage amongst Iraq’s Shia majority population. The following week saw reprisal attacks against a reported 168 Sunni mosques across the country and the killing of hundreds of Sunni civilians by Shia militias. Baghdad’s neighbourhoods had been reasonably intermixed prior to the 2003 invasion, after which ethnic cleansing and forced relocation by militia groups began the process of splitting neighbourhoods along sectarian lines. The eruption of violence in 2006 massively accelerated this process and resulted in a much more polarized demographic distribution between Sunni and Shia Muslims. The Green Zone, the former fortified headquarters of the Iraqi government, was occupied and tightly controlled by coalition forces. Nevertheless, frequent shelling by insurgents and bomb attacks still inflicted damage at the heart of the coalition administration.