Prison gangs are a growing problem in prisons. In recent times, Skarbek's (2011, 2014) governance theory has become increasingly popular in explaining their emergence. Yet this theory downplays the role that deprivation and importation theories can play in understanding the emergence and behaviour of these gangs. This chapter seeks to address this shortcoming by demonstrating how the inclusion of these theories, alongside the governance theory, can enhance our understanding of prison gang emergence and when gang fragmentation or consolidation may occur. Drawing on research conducted in the US and beyond, this chapter argues that a holistic understanding of prison gangs and their monopolisation of power requires a consideration of the importation and deprivation theories, together with Skarbek's (2011, 2014) governance theory. Special attention is paid to the wider role political and social processes may play in influencing whether monopoly power by prison gangs is supported and legitimised or not.