In the Spartacist uprising of January 1919, Mossehaus, the publishing offices in the centre of Berlin, were occupied by the Marxist revolutionaries. According to his son Gerhard (George Mosse), Lachmann-Mosse spent the night in the building debating Rosa Luxembourg and managed to get the next day's "Tageblatt" printed and delivered. He recalled Luxembourg was the most interesting woman he had ever met.