1 of 16
Lady Gaga channeled her more demure side, wearing a red latex gown to meet Queen Elizabeth II after performing for Her Majesty in Blackpool, England, in December 2009. During her onstage performance, however, Gaga attached a 20-foot train to her gown while suspended 30 feet in the air.
2 of 16
A long way from her days as Norma Jeane Baker, the Hollywood bombshell's world collided with that of the monarch (who was the same age as Monroe – 30) in October 1956, when the queen attended a viewing of the movie The Battle of the River Plate (which didn't feature Monroe) in London's Leicester Square.
3 of 16
The Queen of Pop met the Queen of England in November 2002, when Her Majesty – the British one – attended the premiere of the final Pierce Brosnan James Bond flick, Die Another Day, at the Royal Albert Hall. Madonna performed on the soundtrack and had a cameo in the spy flick as Bond's fencing instructor.
4 of 16
JULIE CHRISTIE & WARREN BEATTY
The queen greeted fellow Brit Julie Christie and American movie star Warren Beatty at the London premiere of Born Free in 1966. Beatty and Christie weren't dating yet, but not long after rubbing shoulders with royalty, the duo started a famous Hollywood romance that lasted several years.
5 of 16
When the real-life Queen Elizabeth II met her onscreen doppelgänger from 2006's The Queen during a May 2011 event, it was anything but a chilly reception. Mirren, who has even been invited to tea time with Her Majesty, has said meeting the monarch is a "great honor."
6 of 16
Though he wasn't on Her Majesty's Secret Service at the moment, the tuxedo-clad actor was having a very James Bond moment as he bowed to the monarch at the London premiere of Casino Royale in 2006.
7 of 16
PRESIDENT DWIGHT D. EISENHOWER
Looking less like a meeting between two leaders of the free world and more like a moment at an extended family's backyard barbecue, this August 1959 photo outside Balmoral Castle with Ike, Prince Philip, Princess Anne, the queen and Prince Charles proves that even global politics can be personal.
8 of 16
9 of 16
Who wearing the more distracting shirt? In 1996, the then-president of South Africa synched up with the queen in a hotel in London – a notable meeting in light of Britian's colonialist history in Africa.
10 of 16
Though she had supposedly disgraced the royal family by causing King Edward VIII to renounce the throne for her, the former Duchess of Windsor was still family. In 1967, the scandalized American socialite looked on as her niece by marriage, Queen Elizabeth II, unveiled a plaque to Queen Mary – Wallis's mother-in-law and the queen’s grandmother – at Marlborough House in London.
11 of 16
OZZY OSBOURNE & KERMIT THE FROG
The legendary rocker rubbed elbows with America's favorite felt-skinned frog and Queen Elizabeth II to celebrate her 50-year reign in June 2002.
12 of 16
POPE JOHN PAUL II
Queen Elizabeth II's historic 1980 visit to the Vatican represented the mending of one of the most bitter political-religious splits in European history.
13 of 16
PRESIDENT BARACK OBAMA
In May 2011, Her Majesty smiled politely at a dinner as if nothing had happened when Obama breached protocol by offering a toast during the British national anthem. Despite the political gaffe, the pair looked to have a royally good time.
14 of 16
A year before his death, the wheelchair-bound, recently knighted actor chatted with the queen in 1976 at the new London headquarters of the British Academy of Film and Television Arts, where the queen's daughter, Princess Anne (center), served as president.
15 of 16
It was like the greatest hits of the '80s (international-politics edition) in 1984, when the queen posed for this photo during a high-powered summit at Buckingham Palace with the West German Chancellor Kohl, President Reagan and the British Prime Minister.
16 of 16
Decades before playing Thatcher, the Oscar-winning actress met Queen Elizabeth II in March 1980 after a London screening of her family drama Kramer vs. Kramer, for which Streep won the Academy Award for Best Supporting Actress.
Omarosa Opens Up About Her White House Exit, Plus Annette Bening Responds to Kevin Spacey Allegations
Christina Hendricks Makes a Style Statement, Plus Bella Hadid, Justin Timberlake & More
The Harvey Weinstein Scandal: All of the Hollywood Figures Who Have Spoken Out Against Movie Mogul
Kelsea Ballerini & Morgan Evans Took Shots at the Altar, Plus More Stars' Wedding Secrets
Star Tracks: Celebs on Social