Who becomes a minister? Traditionally, obtaining a cabinet position has been owed to either an extended party career, or, particularly during times of crisis, to relevant expertise. However, in addition to party animals and technocrats, political outsiders with neither relevant service to the party nor suitable expertise succeed time and again in becoming ministers. How can their unlikely rise to the highest echelons of power be explained? We posit that dynamics within parties – intra-party democracy and aspects of power concentration such as party leader autonomy, party factionalisation and federalisation – play a decisive role. To test our hypotheses, we combine novel, granular career data on ministers from 30 European countries (1945-2020) with party-level indicators for statistical analysis. By identifying the drivers behind outsiders’ pathways to government office, our results have important implications for our understanding of the legitimacy and accountability of governments.