Francesco di Sandro Altoni was a 16th century Italian fencing master. Little is known about this master's life; he seems to have been Florentine by birth and he is thought to have been fencing master to the court of Cosimo I de' Medici (1519-1574), Duke of Florence until 1569 and then Grand Duke of Tuscany. At some time during Cosimo's reign as Duke of Florence, Altoni wrote a treatise on fencing entitled Monomachia ovvero Arte di Scherma ("Dueling, or the Art of Defense") and dedicated it to Cosimo. The treatise survives in two manuscript copies, the MS II.iii.315 and MS L.V.23 The treatise begins with a letter and dedication to Cosimo, followed by a preface and introduction. The first weapon introduced is the sword alone, then two swords, sword and dagger, sword and dagger with an armored arm, sword and cape, bucker and targe, rotella, dagger, spadone, pike, partigianone, spiede, and partigiana in the 2nd book. The 3rd book contains the play of the half sword and presses (grappling) among other items.