Records of Prime Ministers of the United Kingdom transitions between reigns, eight Prime Ministers each served under two sovereigns: George III had 14 Prime Ministers serving during his 59-year reign (reigned 1760–1820), beginning with the Duke of Newcastle. The last incumbent, Lord Liverpool, was the only one appointed by his son (the Prince Regent) during the father's final incapacity to rule. In downward numerical order, numbers of Prime Ministers in office during other reigns are: Only six Prime Ministers came to serve office under sovereigns in whose own reigns they were born. The present Prime Minister, Theresa May, is the third Prime Minister to have been born in
Historical rankings of Prime Ministers of the United Kingdom the scores could then be calculated and a league table based on the mean scores. The five Labour prime ministers were, on average, judged to have been the most successful, with a mean of 6.0 (median of 5.9). The three Liberal PMs averaged 5.8 (median of 6.2) and the twelve Conservative PMs 4.8 (median of 4.1). In 2010, the University of Leeds and Woodnewton Associates carried out a survey of 106 academics who specialised in British politics or British history, to rank the performance of all 12 prime ministers who served between 1945 and 2010. Churchill's ranking was thus determined