Aside from large-scale civic mobilisations, no force was more critical to the outcomes of the 2011 Arab uprisings than the armed forces. Nearly a decade after these events, we see militaries across the region in power, once again performing critical roles in state politics. Taking as a point of reference five case studies where uprisings took place in 2011, Tunisia, Egypt, Libya, Yemen and Syria, Philippe Droz-Vincent explores how these armies were able to install themselves for decades under enduring authoritarian regimes, how armies reacted to the 2011 Uprisings, and what role they played in the post-Uprising regime re-formations or collapses. Devoting a chapter to monarchical armies with a special focus on Saudi Arabia and the UAE, Droz-Vincent addresses whether monarchies radically differ from republics, to compare the foundational role of Arab armies in state building, in the Arab world and beyond.