When civil war broke out in South Sudan in December 2013, thousands of soldiers defected from the Sudan People’s Liberation Army (SPLA) and joined the opposition. In response, elites loyal to Kiir’s government mobilized fighters to bolster depleted SPLA forces. One of these groups was known as the Mathiang Anyoor, originally an informal northern-border defence force that would later integrate into the SPLA where its alleged role in some of the conflict’s worst atrocities would unfold.