Historians have documented that in medieval Europe, bargaining over the loyalty of lay magnates and high clergy was most intense during successions and that this often forced monarchs to give political concessions. We argue that matters related to succession predict short-term power-sharing concessions by rulers but that – because they do not permanently alter the balance of power between ruler and elite – they only trigger lasting changes of political institutions if these changes are in the mutual interest of the ruler and the elite groups. It follows that successions are unlikely to have long-term effects on representative institutions but that they may consolidate the rules regulating succession (the succession order). Using the natural deaths of monarchs as an instrument for successions, we confirm these claims with a new dataset that includes fine-grained data on succession and parliament-like assemblies in 16 European polities between 1000 and 1600. These findings shed new light on the development of representative institutions in medieval Europe, on the changes in succession orders that brought about clear rules about primogeniture and on the political leeway of legislatures in authoritarian regimes more generally.