Around 1505-1510, the German landsknecht (soldier) and engineer Paul Dolnstein produced a small sketchbook: a series of vivid drawings accompanied by short first-person annotations. This extraordinary document offers a rare and immediate window into the lived experience of warfare at the dawn of the sixteenth century. Unlike elite chronicles or retrospective memoirs, Dolnstein's work captures life on campaign from the perspective of a participant. Drawing on experiences across the Low Countries, Scandinavia, and Southern Germany, his sketches reflect a life shaped by war on the move, from prolonged sieges to brief skirmishes. This volume presents, for the first time, the complete sketchbook in facsimile, alongside full transcription and translation. Written by an international team of eighteen authors, it examines the work through art and military historical, architectural, experimental archaeological, gender, and other interdisciplinary perspectives. Integrating textual, visual, and archaeological evidence, this study offers new insights into early modern military culture and the realities of life on campaign.