The "Spencer tiara", worn by Princess Diana during her wedding to Prince Charles in 1981, goes on display for the first time in decades at an exhibition at Sotheby's in London that will run from May 28 until June 15 as part of Queen Elizabeth’s Platinum Jubilee celebrations, marking the monarch's 70 years on the throne. The exhibition features other rare and historic tiaras, including one worn by Queen Victoria, as well as portraits of Britain's seven regnant queens, on loan from several institutions and private collections. IMAGES AND SOUNDBITES