King George VI and Queen Elizabeth (wearing her Aquamarine Pine-Flower Tiara, Coronation Necklace and Earrings, and her Coronation Rivière) were joined by Princess Margaret as they attended the Royal Gala Performance of Shakespeare’s ‘Twelfth Night’ at the newly re-opened Old Vic (formally the Royal Victoria Hall) in London on this day in 1950.
Do you have any more pics of this event?
Sadly this is all I’ve found!