Question: who is the uk longest serving prime minister
Answer: Rank by length of terms Prime Minister Length by time served Ministries Party Start of 1st Administration Walpole ! Sir Robert Walpole 20 years , 314 days 6 Whig 1721 Pitt ! William Pitt the Younger 18 years , 343 days 5 Pittite ( Tory ) 1783 Liverpool ! The Earl of Liverpool 14 years , 305 days 5 Tory 1812 Salisbury ! The Marquess of Salisbury 13 years , 252 days 5 Conservative 1885 5 Gladstone ! William Ewart Gladstone 12 years , 126 days Liberal 1868 6 North ! Lord North 12 years , 58 days Tory 1770 7 Thatcher ! Margaret Thatcher 11 years , 209 days Conservative 1979 8 Pelham ! Henry Pelham 10 years , 191 days Whig 1743 9 Blair ! Tony B