The processes of replacement of party leaders are well-published events in media outlets across the world's democracies, but are scarcely analysed by political scientists. In this article we examine the extent to which incumbent party leaders are able to control their own fate in the face of various types of challenges that herald a possible end to their rule. It discusses three related research questions derived from this main objective: (1) what makes incumbents quit? (2) How do incumbents respond to various types of triggers heralding a possible end to their rule? (3) To what extent does incumbent behaviour prior to and following succession affect the fortunes of their successors and their party? We draw on a four-country–eight-party data set of leadership successions between 1945 and 2005, and on findings of in-depth studies of Australian cases to show that not only do Australian leaders get challenged and replaced more frequently than do other leaders, but they are also forced to combat more internal rivalry than their counterparts elsewhere.