Giacomo di GrassiÕs ÒRagione di adoprar sicuramente l'armeÉÓ was originally published in 1570, discussing the use of the sword alone and with various companion weapons, as well as pole arms and the two-handed sword. Upon being translated and published with inferior illustrations in 1594 as ÒGiacomo di Grassi, His True Art of DefenseÉÓ it became the first text on swordplay to be published in English. Unfortunately, the Elizabethan English of the 1594 translation is not always easy on the modern reader, and, critically, suffers from inapt choices of terminology and numerous errors of translation. This wholly new translation has rectified these problems; it was made exclusively with reference to the original Italian text, rendering it into clear modern English, and reproduces the superior illustrations of the original. This translation renders di Grassi readily accessible, to the benefit of scholars, stage combat directors, and historical fencers alike.