Prince Harry made Kate Middleton cry on her wedding day with this sweet gesture

Prince William and Kate Middleton said 'I do' at Westminster Abbey ten years ago, and it is estimated that over two billion people tuned in to watch the royals exchange their vows.

Since 2011, lots of details about their big day have surfaced, including what William said to his father-in-law at the altar and how the Cambridges broke royal protocol on their wedding night.

William chose his brother, Prince Harry, as his best man, and in her 2017 biography, Harry: Life, Loss and Love, Katie Nicholl revealed that the Duke of Sussex's best man speech left Kate 'shedding a tear'.

At the Buckingham Palace reception, Harry gave an 'affectionate' speech which touched the newlyweds.

Ms Nicholl wrote: 'It was affectionate, warm and funny and touched William deeply.

'When he said the couple’s decade-long romance was his inspiration... Kate shed a tear.

'The speech was peppered with Harry’s classic sense of humour, and he ribbed his brother: "William didn’t have a romantic bone in his body before he met Kate, so I knew it was serious when William suddenly started cooing down the phone at Kate."

'Famous for his mimicry, Harry then impersonated his brother calling Kate "Babykins", to much laughter from the guests.”

According to the royal author, Harry also made sure that the venue was perfect for their big day, 'transforming the Throne Room at Buckingham Palace into a nightclub' with disco balls and 'giant glass bowls of Kate and William's favourite Haribo sweets.'

She adds: 'Harry happily took on the role of master of ceremonies and made sure everyone was having a great time.'

How sweet!