Addressing long-term regime trajectories in the Middle East from 1945 to 2011, the paper systematically takes into account all cases of both survival and breakdown of monarchies and republics. It contrasts the pathways of the currently overall surviving monarchies (Bahrain, Jordan, Kuwait, Morocco, Qatar, Oman, Saudi Arabia, UAE) with the trajectories of those regional states which were republics from their beginning (among them, Algeria, Syria and Tunisia) or which became republics after being monarchies in the post-1945 period (Egypt, Iraq, North Yemen, Libya and Iran). Against this historical background, the guiding research question of the paper is: What makes the recent kings’ advantage (general monarchical survival) distinct from the king’s dilemma during previous periods (partial monarchical breakdown from 1952-79)? Using fuzzy-set qualitative comparative analysis (fsQCA), the paper concentrates on seven pertinent explanatory conditions derived from previous research on authoritarianism in general and Middle East regime studies in particular: foreign military support, rents, repression, cooptation, legitimation qua strong ideology or religious heritage, family participation in political decision-making and the degree of social protests. In this, the paper moves beyond current studies in that it, first, combines more than two explanatory conditions and, second, applies them to both cases of survival and breakdown of authoritarian monarchies and republics. The main findings are, first, that at least four different trajectories explain survival and at least three different trajectories highlight the breakdown of authoritarian monarchies and republics in the Middle East over the last six plus decades. The paper also identifies striking differences between the trajectories of monarchies and republics with regard to survival, while the picture is less clear and more heterogeneous for breakdown. Second, it identifies different trajectories for the surviving monarchies in the Gulf states and those beyond (Jordan, Morocco as well as, to a certain degree, North Yemen until 1962 and Oman). This intra-monarchy dichotomy is in line with mainstream monarchy research on the Middle East. However, it is argued that there is not a single sufficient condition – be it rent, legitimation or family participation – which can account for either the survival or the breakdown. The paper concludes by drawing some lessons of these findings for regime trajectories in the Middle East in the context of the ‘Arab Uprisings’.