With the duchess set to be Williamâ€™s Queen Consort when he takes the throne in future, sheâ€™s got a good mentor in the 92-year-old monarch.
Kate began dating William at university in 2003 and she reportedly met the Queen for the first time atÂ Peter and Autumn Phillipsâ€™ wedding in 2008.Â
William proposed in November 2010 and the couple were married in April 2011, when the Queen gave them the titles of the Duke and Duchess of Cambridge.
Kate and Her Majesty had their first official engagement together in Leicester in March 2012, to mark the first date of the Queenâ€™s Diamond Jubilee tour of the UK. Before that, they viewed Kateâ€™s Alexander McQueen wedding dress on display at a Buckingham Palace exhibition.
Since then, theyâ€™ve hosted receptions at the palace together and have been present on the famous balcony for annual events such as Trooping the Colour.
They also enjoyed a girls day out together with Camilla, Duchess of Cornwall in 2012, when they visited Londonâ€™s Fortnum & Mason.
The Duchess of Cambridge appears to have taken some style lessons from Her Majesty, favouring block coloured shift dresses and bold coats. Sheâ€™s even borrowed jewellery from the royal vaults, including tiaras, brooches and earrings.
Take a look at Kate and the Queenâ€™s best moments together over the years.