The first full edition and English translation of the RA I.34 Firework Book. Produced from the early fifteenth century onwards, Firework Books are, broadly speaking, manuals on how to use gunpowder, witnessing a major development in warfare. Surviving in a corpus of some 65, each text has different content and components, but core elements are present throughout. An important example is a manuscript in the collection of the Royal Armouries (RA I.34), written in Early New High German, and (unlike many other manuscripts) still in what appears to be its original format and binding; it also, unusually, contains a number of illustrations. This volume provides the first full edition and English translation of the material, with a detailed analysis of its content and context. It positions the Firework Books at a crucial stage in the development of gunpowder artillery, offering an unparalleled insight into fifteenth-century gunpowder technology at a critical juncture of military and technological change at the end of the Middle Ages.