Brocket Hall early held variously of Hatfield Manor and the Bishop of Ely. Sir Matthew Lamb's son was Peniston Lamb, 1st Viscount Melbourne and he was often visited at Brocket Hall by the Prince Regent, who had a liaison with Lady Melbourne. The next owner was William Lamb, 2nd Viscount Melbourne, who was Queen Victoria's first Prime Minister from 1835–41, when she regularly visited. His wife, Lady Caroline, infamously had an affair with Lord Byron causing Lord Melbourne much embarrassment. For one of his birthdays she held a state banquet in the Saloon, at which she had herself served from a large
William Ponsonby, 1st Baron de Mauley December 1832. At the 1832 UK general election he was elected MP for Dorset and held the seat until 1837. In 1838 he was created Baron de Mauley. Whilst an MP for Poole, Ponsonby and Benjamin Lester opened Poole's first public library in 1830. When the marriage of his sister Lady Caroline Lamb to William Lamb, 2nd Viscount Melbourne, began to break up, he strongly supported Caroline. 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". Ponsonby reminded Melbourne that the Lamb family