William Francis Spencer Ponsonby, 1st Baron de Mauley (31 July 1787 – 16 May 1855), was an English Whig politician who sat in the House of Commons between 1826 and 1837. He was raised to the Peerage in 1838.
When the marriage of his sister Lady Caroline to William Lamb, 2nd Viscount Melbourne, began to break up, he strongly supported Caroline.[8] Unfortunately, he was not noted for tact or intelligence—Melbourne's sister Emily Lamb, Countess Cowper, described him as being universally regarded as "an ass and a jackanapes".[8] Ponsonby reminded Melbourne that the Lamb family were socially parvenu, and that his sister had married beneath her; although true, these remarks were so tactless that Melbourne broke off any further dealings with him.[8]
Family
On 8 August 1814, Ponsonby married Lady Barbara Ashley-Cooper (the only daughter and heir of the 5th Earl of Shaftesbury and a co-heir of the medieval Barony of Mauley, 1789–1844). They had three children:[2]