Heart-warming reason King's Guard breaks royal protocol

The King's Guard is a contingent of infantry responsible for guarding Buckingham Palace and St James's Palace (including Clarence House) in London.

The Guard has strict protocols such as only being allowed to talk under very specific circumstances and is discouraged from showing emotion.

But for one young guard it all became too much.

In a video posted on YouTube the young woman is seen on her horse as visitors take pictures.

But it was when she spotted her parents in the crowd that she valiantly fought back tears.

As her parents approach and start stroking the horse she crumbles before holding her head in her hands and sobbing.

Social media users were quick to offer support.

"So precious, parents come to see her and she's overcome with tears. A great moment for them," one wrote.

"Gosh - I burst into tears too. So much pride and love," a second wrote.

While a third observed it must be "terrible she can't hug her parents while on duty".