LONDON—The Daily Telegraph newspaper scored a major scoop on April 8th when its headline announced that DNA testing has proven that Sir Winston Churchill’s onetime Private Secretary, Sir Anthony Montague Browne, was the biological father of the present Archbishop of Canterbury, the Most Reverend Justin Welby. Montague Browne was an honorary member of The Churchill Centre from 1982 until his death in 2013. His book Long Sunset chronicled the dozen years he worked for Churchill.

In a feature story for the Telegraph, Charles Moore, the official biographer of Margaret Thatcher, explains how he pursued a lead with the full cooperation of the Archbishop that led to the surprising discovery. The Archbishop had always believed that Gavin Welby was his father in fact as well as name. Jane Portal, the Archbishop’s mother now known as Lady Williams of Elvel, acknowledged that she had a relationship with Montague Browne before her sudden marriage to Welby but believed she had been careful about the matter. “It appears that the precautions taken at the time didn’t work,” Lady Williams said in a statement, “and my wonderful son was conceived as a result of this liaison.”

Archbishop Welby already knew that he had close connections with the Churchill circle. His mother worked for Sir Winston herself as a personal secretary from 1949–1955. This was how she came to know Montague Browne. On her mother’s side she is the niece of R. A. B. Butler, who served as a Cabinet minister under Churchill during the war and again in the 1950s. On her father’s side she is the niece of Sir Charles Portal, who served as Chief of the Air Staff for most of the Second World War. Lady Williams attended the 2011 Churchill Conference in London where she spoke along with Hugh Lunghi as part of a panel called “Working with Churchill.”

Anthony Montague Browne was born 8 May 1923. The son of an army colonel, he was educated in Switzerland and at Stowe. His time at Oxford was interrupted by war service. He qualified as an RAF pilot and was assigned to fly Beaufighter aircraft and later the Mosquito. His combat skill in the Middle East and Burma theatres earned him a Distinguished Flying Cross at the end of the war. It was this on top of his post-war service in the Foreign Office and fluent French, Montague Browne believed, which caused Churchill to select him to be his private secretary in October 1952. Sadly he died only days after his son was invested as Archbishop of Canterbury in 2013 before a previously agreed-upon meeting between the two of them could take place.

The Archbishop took the whole business of the revelation with great equanimity. And why not? He already knew that his mother was also a direct descendant of the First Duke of Richmond—the illegitimate son of King Charles II.