Step inside the very room where the Duke of Wellington spent the tense eve of Waterloo — June 17, 1815 — returning exhausted from the Duchess of Richmond's famous Brussels ball before the most consequential battle of the nineteenth century. This extraordinary real-photograph postcard documents the bedroom-turned-museum at Waterloo, its walls bristling with sabers, rifles, and edged weapons recovered from the battlefield, three cannonballs resting on the floorboards, a simple campaign-era armchair beside a plain wooden bed chest, and a white marble mantelpiece crowded with candlesticks and miniature figurines, surmounted by a framed battle panorama and a pair of battered cuirasses — breastplates pierced or dented by musket fire. Published by E. Desaix of Brussels under the "La Belgique Historique" marque déposé imprint, this card belongs to one of the most important early Belgian historical documentation series. Unused, with a pristine blank reverse.