The Hanmer family, among whose members was the early eighteenth-century Speaker, Sir Thomas Hanmer, had long established interests in Flintshire and some, of more recent date, in Buckinghamshire. Hanmer’s father, who succeeded his father, Walden Hanmer, former Member for Sudbury, in 1783, was an active improver of his estate at Bettisfield, where he otherwise lived a very retired life until his death in October 1828. Hanmer served in the Peninsula under the duke of Wellington, notably at Vitoria and Pamplona, where he was aide-de-camp to Sir Robert Hill, and he received a silver war medal with two clasps.
At the general election of 1831 he was returned for Westbury with its patron, Sir Ralph Lopes, on the understanding that he would support parliamentary reform;
