Complex sentence: The sculpture for the Duke of Bedford was based on depictions of the Graces which Canova had previously made, including a 1799 painting, other drawings, and a relief of the Graces that he executed around the same time.
Split into simpler sentences: The sculpture for the Duke of Bedford was based on depictions of the Graces Canova had previously made. These include a painting in 1799, other drawings and a relief of the Graces is also known to have been executed by him around the same time.