Johann Ambrose Rosenstrauch (1768–1835), a German immigrant who owned a fashion store on Kuznetsky Most, witnessed Napoleon's occupation of Moscow. His memorial note about these events, still unknown to historians, is being published for the first time. It tells a dramatic story about the horrors of war, the atrocities of Napoleonic armies, social conflicts among the Russian population and the Moscow fire. The biographical review in the introduction describes the author’s life in Germany and Russia, during which he managed to be an actor, merchant, freemason, Lutheran pastor and met important figures at the Russian imperial court. I.-A. Rosenstrauch is interesting both as a memoirist of the era of 1812, and as a colorful personality, whose life reflected different facets of the history of society and culture of this era. The publication opens the Archivalia Rossica series, a new joint project of the German Historical Institute in Moscow and the New Literary Review publishing house. The profile of the series is the publication of unpublished sources on the history of Russia in the 18th - early 20th centuries from Russian and foreign archives, with parallel text in the original language and translation, as well as detailed scientific commentary by experts. The publications are accompanied by rare visual material.