After the resignation of the Duke of Newcastle as Prime Minister in November 1756, George II dismissed William Pitt (the driving force of the new government) in April 1757 and invited Lord Waldegrave to take over from Newcastle's successor, the Duke of Devonshire, as First Lord of the Treasury.

Accordingly, Devonshire was briefly dismissed and Lord Waldegrave tried to form a government from 8 to 12 June that year but failed to do so and stepped down, partly because he feared that as Prime Minister, he would fall out with his close friend, the King (as his predecessors had done).

The ceremony was performed by Frederick Keppel, the future Bishop of Exeter, and the official witnesses were Sir Edward and his brother, Horace Walpole.

[3] The couple had three daughters: He died of smallpox on 13 April 1763 and, lacking male heirs, his titles passed to his younger brother, John.

[6] After his death, his widow Maria married into the British Royal Family becoming the wife of Prince William Henry, Duke of Gloucester and Edinburgh, King George III's brother.