Peter Knight

In spite of his distinction as a lawyer – the late Master of the Rolls, Lord Denning, once described him as "a solicitor of great astuteness, precision and integrity" – it was his marriage to Miss Kirkwood that brought him to public prominence.

He was seen on television sitting beside her in the This Is Your Life tribute to her in July 1994, and he used his considerable legal acumen to demand retractions, apologies and amendments to a series of books and television documentaries that suggested Miss Kirkwood had a sexual liaison with the Duke of Edinburgh.

On one occasion he went to Buckingham Palace to confront the Duke's advisers about continuing slurs on her reputation that were rumoured to have lost her official recognition in the Honours list.

James Peter Knight was born in Manningham, Bradford, the youngest of the three sons of a Bradford stuff (wool) merchant, James Young Knight, and his wife, Fanny Sampson. He was the great-nephew of the Victorian drama critic Joseph Knight.

Mr Knight was educated at Pocklington School and Leeds University where he gained his bachelor of law degree after studying Roman and constitutional law.

When he was 16, he entered his uncle's Bradford law firm, Sampson, Horner & Co, and in 1938 was admitted as a solicitor of the Supreme Court. He eventually became senior partner and one of the county's leading lawyers.

During the Second World War he served in the Duke of Wellington's (West Riding) Regiment, rising rapidly to the rank of captain, and finally to major. It was in regimental uniform that he married Gwendoline Parker, from Bingley, in 1939. A daughter, Carolyn, was born in 1942, and a son, Nicholas, in 1945.

After demobilisation in 1947, Mr Knight returned to his family law firm. In 1952, he joined the board of Bingley Building Society, later to merge with the Bradford Equitable Building Society.

In 1965, he became senior partner in the law firm after his partner, George Barber, committed suicide. He also became chairman of Bradford Civic Society, president of Bradford Law Society, and Worshipful Master of Priory Lodge of Freemasons in Bingley.

In 1978, after 40 years as a solicitor he retired as senior partner, eventually being succeeded by his son, Nicholas.

Mr Knight became vice-president of Bradford and Bingley Building Society in 1977, and two years later was appointed President.

In 1980, his wife of 41 years died from cancer. He was devastated and went on holiday alone to Portugal's Algarve, and there, at a dinner party in Lagos, met the stage and screen star Pat Kirkwood, who a year earlier had divorced her third husband, the actor, composer and playwright Hubert Gregg.

Mr Knight, who was tall, commanding and charming, described himself as "quite enchanted, as if some spell had been cast over me". They were married in Gibraltar on March 3, 1981, to the initial shock of his children.

When Miss Kirkwood was diagnosed with Alzheimer's Disease, and admitted to an Ilkley nursing in 2004, her husband immersed himself in the writing of a whimsical story, Flummadiddle, set in North Yorkshire, which was published in 2007.

After Miss Kirkwood's death on Christmas Day 2007, Mr Knight authorised the release of letters between his wife and the Duke of Edinburgh that appeared to show that the alleged affair was a myth.

In 2008, when Mr Knight privately published his memoirs, Piety for the Past, he criticised the Palace's failure to defend Miss Kirkwood by issuing a firm denial of the rumour.

In 2009, he published a third book, A Victorian Gentleman, a biography of his grandfather, Bradford wool merchant, John Pike Knight.

He is survived by his son and his daughter, five grand-children, and five great-grandchildren.

Mr Knight's funeral will take place on Thursday at 12.30pm at All Saints' Parish Church, Bingley.