The present study attempts to gather together everything known about the activities of the great Prague lutenist. There are several reasons for making this attempt. First is the fact that Count Losy, as wealthy and influential a man as he was, did not remain a mere dilettante as did so many of his noble contemporaries. Through his works, of which only a portion has come down to us, Losy shows himself to be more than an amateur of his instrument; his talent and training enabled him to achieve higher things. Second, he and the somewhat older Esajas Reusner are the sole representatives of the early German baroque school of luteplaying and, thus, are of considerable importance. The proof of their importance rests on the fact that their music continued to be quoted long after their deaths. Measured by the number of surviving manuscript copies, the esteem of Losy’s work is equalled only by that enjoyed by Ennemond and Denis Gaultier. Last, but not least, Losy’s school of lute playing constitutesan essential part of Bohemian musical history.