The romantic career of that unhappy favorite of Queen Elizabeth, Robert Devereux, second Earl of Essex, like the histories of Mary Stuart and of the Maréchal de Biron, has been often used as a subject for tragedy in Spanish, French, Italian, German, and English. Several of these plays have been studied more or less carefully at different times, so that I shall not do more than summarize those versions briefly before passing on to my main subject, the relation between Niccolo Biancolelli's Regina Statista d'Inghilterra and its commedia dell'Arte variants, of which the one presented here is hitherto unpublished.