Meghan Markle joined the Queen at Westminster Abbey for a church service to mark Commonwealth Day on Monday.
For the former American actress it was her first engagement with the monarch and marks a major milestone ahead of her marriage to Prince Harry on May 19.
The multi-faith event celebrates the 53 Commonwealth countries each year and this year hosted Prince Charles, the Duchess of Cornwall, the Duke and Duchess of Cambridge and the Prime Minister, who read a Bible passage during the service.
The Queen in her address praised the 'Commonwealth connection' and said diversity is 'a cause for celebration'.
She said: 'Through exchanging ideas, and seeing life from other perspectives, we grow in understanding and work more collaboratively towards a common future.
'There is a very special value in the insights we gain through the Commonwealth connection; shared inheritances help us overcome difference so that diversity is a cause for celebration rather than division.'
Members of the Royal Family along with other politicians including Labour leader Jeremy Corbyn, Scottish First Minister Nicola Sturgeon and former prime minister John Major were treated to performances by the Ghanaian drum collective One-Drum and spoken word artist Jaspreet Kaur.
Liam Payne, who sang Waiting On The World To Change by John Mayer, also performed to the 2,000-strong congregation.
It comes ahead of a major gathering of Commonwealth leaders in London next month.
Ms Markle described the service as 'beautiful, especially the choir and the music,' according to a visiting teacher, adding that it was 'great to see people from all over the world so well represented at the service'.
Responding to questions about her wedding, she confessed she is 'very, very excited', according to the Telegraph.