This article tells the story of Marianna Florenzi, an Italian translator who made one of the first translations of the Monadologie of Leibniz. Nowadays her name is almost forgotten, but she was the one to propagate Leibniz’s thoughts in Italy. She dispersed a whole ideological movement (Giordano Bruno, Friedrich Wilhelm von Schelling, etc.) by translating, writing and commenting upon these authors. Furthermore, she wrote several unpublished works on pantheism, communism, socialism, the temporary power of the pope.