The sitter was the only daughter and (after the deaths of her brothers, 2nd Viscount Melbourne, the Prime Minister, and Lord Beauvale) sole heiress of Sir Peniston Lamb, 1st Viscount Melbourne (1748-1828), and Elizabeth (1749-1818) (see lot 44), daughter of Sir Ralph Milbanke, 5th Bt., of Halnaby Hall, Yorkshire. She married firstly Peter Leopold, 5th Earl Cowper (1776-1837), in 1805, and had by him three sons and two daughters. In 1839 she married secondly Henry John, 3rd Viscount Palmerston, K.G. (1784-1865). Lady Palmerston's charm, intellect and tact was to be a powerful support to Lord Palmerston political career. The informal diplomatic work carried out in her salon laid the way for many negotiations during her husband's tenure as Prime Minister. Selections from her correspondence were published by her great-granddaughter Mabell, Countess of Airlie, Lady Palmerston and her Times, 1925.
We are grateful to Hugh Belsey for his help in cataloguing this work.