The term "Prime Minister" appears at this time as an unofficial title for the leader of the government, usually the head of the Treasury. Jonathan Swift, for example, wrote that in 1713 there had been "those who are now commonly called Prime Minister among us", referring to Sidney Godolphin, 1st Earl of Godolphin and Robert Harley, Queen Anne's Lord Treasurers and chief ministers. Since 1721, every head of the Sovereign's government – with one exception in the 18th century (William Pitt the Elder) and one in the 19th (Lord Salisbury) – has been First Lord of the Treasury.