Prince William with Kate Middleton at a rugby match

London, Oct. 14: The Queen’s 50,000-acre Balmoral estate was the setting for Kate Middleton’s intimate weekend with Prince William — and the backdrop for the first public photograph of her with the man tipped to become her future father-in-law.

It is the magnificent Highland location where Prince Philip proposed to the Queen and Edward VIII spent romantic weekends with Wallis Simpson.

Dressed in a camouflage jacket, dark jeans, leg warmers and gaiters over her boots, Kate could be seen at one point lying on the ground — seemingly to prepare the sights of her gun before shooting.

With a pair of binoculars around her neck and a relaxed shooting position, she looked a veteran stalker.

Prince Charles, wearing a waterproof coat over a jacket and tie, and sporting plus fours, was standing just a few feet away from Kate apparently supervising the proceedings.

Protection office kept a watchful eye from a public road on the estate but William was nowhere to be seen.

Kate and William, both 25, are spending a long weekend at Birkhall, Prince Charles’s home on the Scottish estate which he took over five years ago when the Queen Mother died.

The couple are the guests of Prince Charles and the Duchess of Cornwall — thereby fuelling speculation of a possible engagement.

The couple visited Balmoral when they were both students at St Andrews University — where they met — but this is the first time they have returned to the estate since they renewed their romance.

Prince Charles’s decision to invite Kate to Balmoral for a family weekend marks a significant progression in the young couple’s relationship.

Prince Charles will relish the fact that Kate has joined in so enthusiastically with country pursuits and that she appears to enjoy her time at Balmoral.

His first wife, the late, Diana, Princess of Wales, always resented being “dragged” to the estate, preferring to spend time in London.

Other family friends have also joined the house party for the weekend.

William and Kate’s romance appears to be going from strength to strength but sources close to the couple say that any engagement announcement is still some way off — not until next year at the earliest.

Bookmakers, however, are so convinced that the young couple will marry that they have stopped taking bets on whether it will happen.