Henry George Percy, 7th Duke of Northumberland,, styled Lord Warkworth between 1865 and 1867 and Earl Percy between 1867 and 1899, was a British Conservative politician. He served as Treasurer of the Household under Benjamin Disraeli between 1874 and 1875 and was Chairman of the National Union of Conservative and Constitutional Associations from 1879 to 1883.

George John Douglas Campbell, 8th and 1st Duke of Argyll, was a British polymath and Liberal statesman. He made a significant geological discovery in the 1850s when his tenant found fossilized leaves embedded among basalt lava on the Island of Mull. He also helped to popularize ornithology and was one of the first to give a detailed account of the principles of bird flight in the hopes of advancing artificial aerial navigation. His literary output was extensive writing on topics varying from science and theology to economy and politics. In addition to this, he served prominently in the administrations of Lord Aberdeen, Lord Palmerston, John Russell and William Gladstone.