Title: Epistolae obscurorum virorum
Description: Authorship of the Epistolae, written to Ortuinus Gratius, was formerly attributed to Reuchlin, Erasmus, Hutten and others. More recent research has made it almost certain that Crotus Rubeanus and Ulrich von Hutten were the principal contributors.

To Crotus are credited the first 41 letters; to Hutten the 7 letters added later to the original series and most of the letters of the second series, with the possible co-operation of a third person, Hermann von dem Busche. The authorship of the rest remains doubtful.