The label for the British spy believed to have aided the third man, (Harold Kim Philby), who in turn had been in league with two other men moles in the British government, Guy Burgess and Donald Maclean. In 1963, when Philby was unmasked as a Soviet spy, British intelligence officials sought a fourth man, long suspected to be Sir Anthony Blunt, a former Intelligence Officer and a highly respected art historian who was the curator of the queen's paintings. Blunt was, in fact, the fourth man and speculation arose about a "fifth man."
