This article reviews books which test the personalization of politics, looking at different dimensions of the growing importance of leaders over time, namely for political parties, in electoral behaviour and in the media. Only recently have wide-ranging comparative longitudinal studies on leaders been carried out. The personalization thesis is not equally demonstrated across all dimensions. Indeed, we find something of a puzzle: There is no strong trend towards personalization of party organizations, whereas in electoral behaviour the evidence points to the increasing use by voters of leaders as heuristics. This attests to the decline of the importance of parties. The personalization of media may be the mechanism which explains the change in voting behaviour, and the third and final section of the review looks into that arena. We conclude with some suggestions on further research on the personalization of politics.