A young woman whirls about on the dancefloor, seemingly lost in the music, her expression is one of happiness.
A closer look reveals that this is the Queen, then Princess Elizabeth, letting loose with Prince Philip at a square dance held in their honour in Ottawa.
The image was taken during their first visit to Canada in 1951. And such is the affection felt towards the monarchy in much of the country that subsequent tours have nearly always give rise to similar pictures of gaiety as the Duke and Duchess of Cambridge will, no doubt, find out.
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Since then the sovereign has been there 22 times, making it the Commonwealth country that has hosted her most often.
The Prince of Wales and Princess Diana went there twice during their marriage, on the second occasion taking William and Harry. This time the family visited Ontario, Ottawa, Sudbury, Kingston and Niagara Falls.
And no one in Vancouver can forget Charles' poignant return just months after Diana's death for a ski trip with his sons.
The heir to the throne has since been back with The Duchess of Cornwall.
Prince Andrew and the Duchess of York also made history, gamely dressing up in historic costume, rowing through the Thelon River and visiting The Giant Mine in Yellowknife.
William and Kate are promised a thrilling time too, with a rodeo visit and dragon boat race, in which they'll be pitted against each other, both on their agenda.