Oldfield himself believed that, although Green probably inspired le Carré, the character of Smiley was primarily based on John Bingham, 7th Baron Clanmorris, who had been le Carré's boss when he originally joined MI5 prior to his career in MI6. In 1999, le Carré confirmed that Bingham was also an inspiration for Smiley, and in 2000 went further, writing in an introduction to a reissue of one of Bingham's novels that "He had been one of two men who had gone into the making of George Smiley. Nobody who knew John and the work he was doing could have missed the description of Smiley in my first novel".