Horror and Harm: Rudolf von Deventer’s Treatise on Gunpowder and Fireworks, c. 1585 offers a transcription and translation from German into modern English of a unique and spectacularly illustrated sixteenth-century manuscript on war and festival culture during the reign of the Danish King Frederik II (r. 1559–88). The manuscript, written in German by the King’s specialist in artillery Rudolf von Deventer, presents instructions to produce firearms for defence against the archenemies of the Christian regime as well as formulae for the production of fireworks for pleasure. The manuscript includes lavishly coloured illustrations of battle scenes, weapons and moving mechanical fireworks such as girandoles and dragons.

Horror and Harm constitutes an exceptional insight into Northern European war, artillery, technology, fireworks and festival culture in the Early Modern period. As an early form of manual, von Deventer’s book is put into perspective in a foreword by the historian of science Pamela H. Smith and a series of introductory texts.