The Duke of Cambridge shares a close bond with his royal cousins, including Zara Tindall (née Phillips), and as Prince William turned 39 on Monday, fans remembered an adorable childhood moment between the pair.
The sweet unearthed video showed three-year-old Zara planting kisses on a nearly two-year-old William as the royal family watched the RAF flypast from the Buckingham Palace balcony in 1984 to mark the Queen's official birthday.
Diana, Princess of Wales, who kept a watchful eye on the young royals throughout, was pregnant with Prince Harry at the time.
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WATCH: Zara Phillips plants kisses on Prince William during balcony appearance
William could be seen whipping his head around to look at his mother after Zara threw her arms around him. Diana beamed at Princess Michael of Kent and the Queen Mother after witnessing the adorable moment between the royal cousins.
The occasion marked both of the young royals' debuts at Trooping the Colour, alongside Zara's older brother, Peter Phillips, and Princess Michael of Kent's eldest child, Lord Frederick Windsor.
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William was front and centre on the balcony with his cousins
William's bond with cousin Zara has continued into adulthood and in 2019, the Cambridges and the Tindalls were spotted enjoying a family day out together at a fairground in Norfolk.
William and Kate are parents to Prince George, seven, Princess Charlotte, six, and Prince Louis, three, while Zara and husband Mike also have three children; Mia, seven, Lena, three, and Lucas, who was born in March.
In recent years, the youngest generation of royals have also amused fans with their mischievous antics on the Buckingham Palace balcony.
Prince George and Peter and Autumn Phillips' eldest daughter, Savannah, had one of the most memorable moments at Trooping the Colour in 2018 when Savannah put her hand over her cousin's mouth to stop him singing.
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