In his What Happens in Hamlet, J. D. Wilson studies Hamlet's melancholy in the light of Renaissance beliefs, and especially those indicated in Bright's Treatise of Melancholie, to which Shakespeare seems to have been indebted for a number of ideas as well as turns of phrase. Significantly, as Wilson shows, the melancholy man was not only “prone to spectral visitations,” but was also aggravated in his condition by thwarted ambition; further, he “ponders and debates long, and does not act until his blood is up: then acts vigorously.” We can reasonably agree with this author that a knowledge of the contemporary corpus of doctrines and beliefs is important for an understanding of Hamlet's character and motivation, in which the thread of melancholy evidently connects several important elements. In the Introduction to his edition of Shakespeare's play, Wilson mentions another source for a melancholy Hamlet: the Histoires tragiques of François de Belleferest, which is recognized as the most immediate extant source of the play. Belleferest does, says Wilson, make a “definite reference to Amleth's [Hamlet's] over-great melancholy,” following a hint already to be found in the version of Saxo Grammaticus (Belleforest's source); but Wilson does no more than call attention to the reference, without noting Belleforest's additional remarks on the subject, and specifically denying to either source any other contributions to Hamlet's character. It will be the purpose of this article to show that not only the melancholy complex, but also other important facets of Hamlet's character have a probable basis in Saxo and Belleferest, and especially in the latter.