Records of Prime Ministers of the United Kingdom the middle name until the 1980s.) The richest Prime Minister was Lord Derby, with a personal fortune of over £7 million (about £444 million in today's money). The poorest was William Pitt the Younger, who was £40,000 (now over £1 million) in debt by 1800. Three Prime Ministers ultimately died as a result of accidents: Records of Prime Ministers of the United Kingdom The article lists the records of Prime Ministers of Great Britain and of the United Kingdom since 1721. The Prime Minister with the longest single term was Sir Robert Walpole, lasting 20 years and 315 days from
Records of Prime Ministers of the United Kingdom Russell, was connected in different ways to two further Prime Ministers: Frederick North, Lord North (later Lord Guilford) and Lord ButeNorth's granddaughter, Lady Maria North, married Bute's great-grandson John Crichton-Stuart, 2nd Marquess of Bute. The Duke of Wellington and Lord SalisburySalisbury's paternal aunt Lady Georgiana Cecil married Henry Wellesley, 1st Baron Cowley, Wellington's brother. Lord Derby and Lord RoseberyRosebery's son Neil Primrose, married in 1915 Lady Victoria Stanley, daughter of the 17th Earl of Derby and great-granddaughter of the 14th Earl. The Prime Minister who had the most children is Lord Grey, who fathered 17 children (16 legitimate, one illegitimate).