This article presents an edition with introduction and commentary of two unpublished letters that Ulrich von Wilamowitz-Moellendorff wrote to the art historian and cultural scholar Aby Warburg in the 1920 s. The edition completes a correspondence that includes a letter from Warburg that has already been published several times. The two letters cast light on the hitherto barely known relation of Wilamowitz to Warburg himself and to his Kulturwissenschaftliche Bibliothek in Hamburg. They centre on the Warburg Library’s special research interest, (...) namely the influence of the ancient world on later cultural periods, especially the Renaissance. (shrink)