Queen Elizabeth II’s Platinum Jubilee with a sweet #TBT snapshot.The Beatles legend, 79, posted a classic photo Thursday of himself and the 96-year-old monarch posing together at the royal opening of the Liverpool Institute for Performing Arts in 1996.The beloved rock icon captioned the image: “70 beautiful years of Queen Elizabeth the second. Congrats ma’am! And thanks.”In the smiling pic, the queen is seen looking on as she sports a bright baby-blue hat and dress while carrying a bouquet of white flowers.McCartney donned a dark suit and a blue-and-yellow patterned tie for the occasion.The pair had met decades prior to the ’90s event, having crossed paths in 1965.During the swinging ’60s, McCartney and his bandmates — Ringo Starr, John Lennon and George Harrison — were awarded with Member of the Order of the British Empire medals, better known as MBEs, by the sovereign at Buckingham Palace.McCartney was later knighted in 1997.The British queen celebrated 70 years since her coronation on June 2 with parties celebrating her Platinum Jubilee.