Lansdowne, Henry, third Marquis of, liberal politician, born in London; educated at Edinburgh and Cambridge; sat in the Commons as member for Calne from 1801 and for Cambridge from 1806, and succeeded to the peerage in 1809; on the accession of the Liberals to power he joined the Cabinet of Canning, presided at the Foreign Office in Goderich's administration, became President of the Council under Lord Grey in 1830, and, twice refusing the Premiership, was a member of every Liberal Government till 1858, when he retired from public life; he was the trusted adviser of his party, and friend of the Queen till his death (1780‒1863).
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Lannes, Jean, Duc de Montebello * Lansdowne, Henry, fifth Marquis of