In 2012, a British couple decided to send a wedding invitation to Elizabeth II as a joke. They had no connection to royalty and did not expect anything to happen.
Their ceremony was held at Manchester Town Hall on the same day the Queen had an official visit for her Diamond Jubilee. They received a response from the palace declining the invitation, so everything seemed destined to remain a simple anecdote until after the “I do”.
After the ceremony, they were asked to wait a few minutes in a hallway. Shortly afterward, the Queen appeared to personally congratulate them, chat with them, and pose for photos, surprising everyone present.
It was not a formal attendance at the wedding, but that unexpected gesture turned the moment into an unforgettable memory for the couple.