The heartbreaking reason Prince Philip will be spending Valentine's Day alone

Queen Elizabeth II and Prince Philip have been married for 72 years, but they are spending today apart.

Prince Philip lives full time on the royal Sandringham Estate in Norfolk, where the Queen has been staying for an extended winter break.

But now, she has returned to her home at Buckingham Palace in London to return to royal duties full time.

The monarch took the train from King’s Lynn train station in Norfolk to return to her base in London.

Meanwhile, Philip lives in Wood Farm, a red-brick five-bedroom home in the grounds of Sandringham Estate.

A friend of Philip said the Queen feels he has earned himself a 'proper retirement' after being 'on duty' since the pair married in 1947.

They said, 'She knows him too well, if he was still at the centre of royal life he’d feel he had to be involved.

'Being at Wood Farm means he’s not too far away, but far enough to be able to relax.'

It's no wonder the Queen is keen for her husband to focus on relaxing, given his recent health problems.

During the Christmas break, Prince Philip, 98, was admitted to King Edward VII’s hospital in London to receive treatment for a 'pre-existing condition.'

But he was seen walking out of the hospital after just a few days of treatment and returned to Sandringham in time for Christmas celebrations.

The Queen's return to the capital comes after news that her grandson, Peter Phillips, and his wife Autumn are divorcing.

They announced their divorce in a statement, saying they would continue to live in Gloucestershire and will co-parent their daughters Savannah and Isla.

A source revealed that while the Queen is 'sad at the decision, both families are hugely supportive of them both and the girls.'