Complex sentence: The drawing is cut from a copy of the Sforziada, a printed book containing an account of the career of Ludovico Sforza's father Francesco Sforza and his family, some copies of which were printed on vellum and had added illumination.
Split into simpler sentences: The drawing is cut from a copy of the Sforziada, a printed book containing an account of the career of Ludovico Sforza's father Francesco Sforza and his family. Some copies of which were printed on vellum and had added illumination.