So what is the truth about Philip and those ‘affairs’? Latest part of our portrait tells how rumours have dogged the Queen and Duke of Edinburgh’s 70-year marriage

So what is known about her association with the Prince? Years later, Pat said that one evening, after she’d performed in the musical Starlight Roof at the London Hippodrome, Baron had taken and an equerry to her dressing room.

The foursome then went out to dinner at Les Ambassadeurs Club in Hamilton Place, run by a Polish ex-wrestler. Afterwards, they carried on — at Philip’s request — to the Milroy Club for some music and dancing. According to Pat, the Prince wouldn’t let her sit down, dancing with her to whatever the band played. They stayed out until dawn and had scrambled eggs at Baron’s flat.

Pat insisted that the only time she’d ever met the Prince again was at theatrical command performances.

After she died in 2007, her fourth husband Peter Knight announced that, at her request, he’d one day give ‘correspondence’ between Pat and the Duke of Edinburgh’ to Philip’s official biographer. It would prove that there was no illicit relationship, he said.

This didn’t explain, however, why Pat and the Prince were corresponding with each other at all.

Another woman with whom the Prince has been romantically linked is Hélène Cordet, formerly Helene Foufounis. They became friends as children when they spent holidays together at her parents’ villa in Le Touquet, France.

Helene, who became the hostess of the BBC variety show Café Continental, had two children while separated from her first husband, but refused to reveal who their father was. So when Philip elected to become godfather to both, some assumed that it must be him.

Despite this, Helene allowed the paternity of her children to remain a mystery — though one of her sons has flatly denied that the Prince is his father.

The rumour mill has kept on grinding, even alleging he had a relationship with Sarah Ferguson’s mother, Susan Barrantes. His alleged indiscretions include:

the Countess of Westmorland, wife of the Queen’s Master of the Horse; the novelist Daphne du Maurier, who was married to ‘Boy’ Browning, former Comptroller of the Royal Household; the actresses Merle Oberon and Anna Massey; the TV personality Katie Boyle; the Duchess of Abercorn, wife of the Lord Steward of the Royal Household; his cousin, Princess Alexandra; and his carriage-driving companion Lady Brabourne (now Lady Mountbatten).