Ponsonby, William Francis Spencer, 1st Baron De Mauley (1787 -1855)
William Francis Spencer Ponsonby was the third son of Frederick Ponsonby, 3rd Earl of Bessborough, and Henrietta Frances Spencer, second daughter of the 1st Earl Spencer. Mr Ponsonby was Member of Parliament for Poole, for Knaresborough and for Dorset. He married, 8 August 1814, Barbara, only daughter and heir of Anthony Ashley Cooper, 5th Earl of Shaftesbury, and co heir of the ancient Barony of De Mauley. He was created Baron De Mauley of Canford in Dorset 10 July 1838. His library was sold with that of his father at Christies in 1897.