It is unexpected in any era to find a woman writing a book on the art of warfare, but in the fifteenth century it was unbelievable. Not surprisingly, therefore, Christine de Pizan's The Book of Deeds of Arms and of Chivalry, written around 1410, has often been regarded with disdain. Many have assumed that Christine was simply copying or pilfering earlier military manuals. But, as Sumner Willard and Charity Cannon Willard show in this faithful English translation, The Book of Deeds of Arms and of Chivalry contains much that is original to Christine. As a military manual it tells us a great deal about the strategy, tactics, and technology of medieval warfare and is one of our most important sources for early gunpowder weapon technology. It also includes a fascinating discussion of Just War. Since the end of the fifteenth century, The Book of Deeds of Arms and of Chivalry has been available primarily through Antoine Vérard's imprint of 1488 or William Caxton's 1489 translation, The Book of the Order of Chivalry. Vérard even suggested that the work was his own translation of the Roman writer Vegetius, making no mention of Christine 's name. Caxton attributed the work to Christine, but it is impossible to identify the manuscript he used for his translation. Moreoever, both translations are inaccurate. The Willards correct these inaccuracies in a clear and easy-to-read translation, which they supplement with notes and an introduction that will greatly benefit students, scholars, and enthusiasts alike. Publication of this work should change our perception both of medieval warfare and of Christine de Pizan.