Royals British Royal Family British Royal Family Weddings Inside the Night Princess Margaret's 'Flirting' with Richard Burton Upset Wife Elizabeth Taylor "Elizabeth was getting more and more cross as the evening went on," Richard Burton's friend says By Simon Perry Simon Perry Simon Perry is a writer and correspondent at PEOPLE. He has more than 25 years’ experience at PEOPLE covering the royals, human interest and celebrity. People Editorial Guidelines Published on May 7, 2020 02:37PM EDT Princess Margaret liked a party, and she liked hanging out with movie stars and other leading showbiz figures of her day. But when the two worlds collided one evening, the princess almost got into hot water with screen queen Elizabeth Taylor. Fifty-one years ago, when Taylor and husband Richard Burton were in London celebrating the royal premiere of the film Staircase, Queen Elizabeth’s younger sister — who died in 2002 — joined them and friends for dinner at the Dorchester hotel. “Elizabeth was getting more and more cross as the evening went on because Princess Margaret was flirting terribly with Richard," Burton’s friend and lawyer Brian Eagles, 83, told The Times in the U.K. "He was flirting back and Elizabeth was getting very perturbed about it.” Princess Margaret's Lady-in-Waiting Lady Glenconner Opens Up: 'We Would Roar With Laughter' Princess Margaret greets Elizabeth Taylor and Richard Burton. Hulton-Deutsch Collection/CORBIS/Corbis via Getty Princess Margaret greets Elizabeth Taylor and Richard Burton. Douglas Miller/Keystone/Hulton Archive/Getty Eagles’ longtime association with Burton, who was famously twice married to Taylor, brought him close to the tempestuous couple, and Taylor once entrusted him with her most precious diamonds, the lawyer (who is the U.K.’s oldest practicing solicitor) revealed. “For years I was the only person in the world that had the key to [Taylor’s] jewelry, which was kept in a bank vault in England,” he said. And when Taylor couldn’t decide what pieces to take with her to wear at Princess Grace of Monaco’s 40th birthday party, he had to use all his guile to get them through various border crossings. Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! Despite exchange controls in 1969 putting a £50 limit on the value of goods that could leave Britain, Eagles “managed to persuade customs officials to let him through” with two suitcases of jewels, The Times reported.