sentences:  By custom, prime ministers retiring from the Commons were usually offered earldoms, so a dukedom was a sign of special honour.One title that was considered was "Duke of London", a city whose name had never been used in a peerage title.Churchill had represented divisions of three different counties in Parliament, and his home, Chartwell, was in a fourth, so the city in which he had spent most of his time during fifty years in politics was seen as a suitable choice.