William Henry Cavendish-Bentinck-Scott, 4th Duke of Portland

Born in 1768, William Henry Cavendish-Bentinck succeeded as 4th Duke of Portland in 1809, on the death of his father, sometime Prime Minister and Whig leader. While Marquis of Titchfield he sat in the House of Commons and later as Duke in the Lords, he had limited engagement with politics, which he left to his father, brother-in-law (George Canning) and son. Like his grandfather he married a wealthy heiress, expunging the debts of his father. Henrietta Scott brought substantial estates to the marriage, including active and potential Ayrshire coal mines, which necessitated the construction of a waggon way to a new harbour at Troon. When he inherited the family estates he was able to tackle its debts from revenues from the new Scottish properties, through agricultural improvement and urban development in Marylebone. He left the 5th Duke a massive and solvent estate across Great Britain.