Complex sentence: Some of his finest works were commissioned by the Astley family of Melton Constable, including one of a Musical Party, and a double portrait of Edward and Blanche Astley the children of Sir Jacob Astley, 3rd Bt.
Split into simpler sentences: Some of his finest works were commissioned by the Astley family of Melton Constable, including one of a Musical Party. He painted the children of Sir Jacob Astley, 3rd Bt.