In 1889, Hermann Usener (1834-1905) published his most famous work, "Das Weihnachtsfest". At the time, he was one of Germany's leading classicists and the most prominent historian of ancient Greek and Roman religion, working with a particular focus on mythology. 1 His book, which has not yet been replaced as a study of the origin of Christmas, was the first that analysed a Christian festival as if it was just like a pagan Roman celebration. In other words, it was the first that studied a major Christian feast not from a theological perspective but from a purely historical point of view. 2 However, Usener's interest was not just historical. He was deeply committed to purifying the Christian Church of his day, in particular the Roman Catholic one, from its pagan survivals in order to build a church that would unite all Germans, both Protestants and Roman Catholics. To that end, Usener also studied the lives of saints, such as Tychon, Marina and Pelagia, in search of pagan antecedents. 3 Given his great influence, it is not surprising that some of his pupils also claimed that the early Christian saints either performed the same function as the ancient Greek cultic heroes or had even developed from this cultic context. 4 At the beginning of the 20 th century, anthropologists and historians of re- This contribution is the fruit of my stay as Visiting Professor at the Collaborative Research Center / Sonderforschungsbereich 948, Freiburg im Breisgau, September to December 2014. I am most grateful to Andreas Friedrich for making my stay in Freiburg so very enjoyable, and to audiences in Freiburg (2014), Cracow (2015), Sydney (Macquarie University), Erfurt and Bergen (2016), Bochum, Ghent, Frankfurt, Graz and Cologne (2017) for interesting discussions. I am also much indebted for clarifying comments to Jitse Dijkstra, Ton Hilhorst, Ralf von den Hoff (on § 1), and Marc van Uytfanghe.