THE romance between Prince Philip of Greece and Princess Elizabeth sprang out of a summer encounter on the tennis courts in 1939.

The future couple, who are distant cousins, had been at the same gatherings on a number of occasions.

When Philip was aged 13 and the Princess was eight, they both attended the 1934 wedding of Philip’s cousin, Princess Marina, later Duchess of Kent, and Elizabeth’s uncle, Prince George, Duke of Kent. They were also both guests at the coronation of George VI in 1937.

But it was at the Royal Naval College in Dartmouth, Devon, when King George VI and Queen Elizabeth visited with their two daughters, that the pair had their first publicised meeting in July 1939.

King George VI’s official biographer, Sir John Wheeler-Bennett said the Princess fell for Philip at once on that pivotal weekend.

“This was the man with whom Princess Elizabeth had been in love from their first meeting,’’ he wrote.

Philip, who was just 18, was introduced to 13-year-old Elizabeth at the house of the Captain of the College, later Admiral Sir Frederick Dalrymple-Hamilton.

Two of the other cadets invited along had contracted mumps, so Philip was the only one who met the royal family that day. Handsome, blond-haired, athletic Philip caught Lilibet’s eye as he entertained her by jumping over tennis nets.

Marion Crawford, Elizabeth’s governess, recalled: “I thought he showed off a good deal.”

But the Princess was entranced. “She never took her eyes off him the whole time,” ‘Crawfie’ wrote.

The pair maintained a regular correspondence and met on several more occasions. Philip was also invited to spend the Christmas of 1943 with the royal family at Windsor.

In an attempt to stop any gossip about their relationship, the Princess switched the photograph of a clean-shaven Philip which she kept in her room, with one of him sporting a large beard.

But by the end of the war newspapers were already speculating about romance.

Elizabeth and Philip began to talk of getting engaged while at Balmoral during the summer of 1946, but any confirmation was delayed until the Princess turned 21 and had returned from a key royal tour of South Africa with her parents.

Philip applied for British nationality and in February 1947 became a naturalised British subject, renouncing his Greek royal title and adopting the surname of Mountbatten.

Five months later, in July 1947, it was officially announced by Buckingham Palace that he was to marry the Princess.