Photographer Antony Armstrong-Jones proposed to Princess Margaret with a ruby and diamond ring modelled after a rose bud—and he had the cutest reason for choosing this design: Margaret's middle name is Rose. Photo: Getty

Rainier III of Monaco proposed to Grace Kelly with a Cartier eternity band made of rubies and diamonds, but exchanged it for a bigger diamond from the same brand (featuring a 10.47 carat emerald-cut stone) when he realised that he hadn't ascribed to the traditional "go big or go home" way of life. Fun fact: Grace's family had to fork over a dowry of $2 million for the wedding. Photo: Getty

Camilla was gifted a gorgeous Art Deco ring that belonged to the Queen Mother when Charles proposed. Apparently, the Queen Mother herself was given the ring as a gift at the birth of Elizabeth II, so it has an extremely important royal history. Photo: Getty

Zara's ring from rugby player Mike Tindall is custom-designed diamond and platinum—a pretty big departure from her fellow royals' colourful stones. Photo: Getty

Prince Andrew gave Fergie a Burmese ruby ring he helped design from royal favourite House of Garrard—which is said to have been picked thanks to the fact that it matched her hair. Photo: Getty

Daniel Westling gave Crown Princess Victoria of Sweden (who will one day be queen) a diamond solitaire set in white gold. It's an incredibly simple and classic ring, said to be designed by the official court jewellers of King Carl XVI Gustaf. Photo: Getty

Speaking of patriotic rings, Joachim of Denmark asked Marie Cavallier to marry him with a ring meant to reflect her home flag of France. During the couple's engagement conference she explained the choice, saying, “so I can keep a bit of the French.” Photo: Getty

When Prince Frederik of Denmark proposed, he gave Mary Donaldson a diamond ring flanked by rubies. He's said to have chosen the stones because they're the colour of the Danish flag. Very patriotic. (FYI, Mary is set to become queen once Frederik succeeds to the throne.) Photo: Getty

As is the British royal tradition, Princess Anne was given a sapphire and diamond ring when her first husband lieutenant Mark Phillips proposed (pictured here). She was also given a sapphire and diamond ring during her second engagement to Royal Navy commander Tim Laurence. Photo: Getty

Then-Prince Felipe VI of Spain proposed to journalist Letizia Ortiz with a pretty unusual ring. Instead of featuring a diamond solitaire, he chose a ring with a row of diamonds set between two white gold bands. Photo: Getty

King Edward VIII famously abdicated the throne in order to marry Wallis Simpson (she was twice divorced—not exactly Queen material at the time), and gave her a Cartier emerald ring that was inscribed, "We are ours now 27 X 36." Those numbers represent the date of their engagement. Photo: Getty

Princess Soraya was married to Reza Pahlavi (the Shah of Iran), and their wedding was insanely epic, in part thanks to her gloriously massive 22.37 Harry Winston diamond. Also, fun fact: the Shah asked Soraya to marry him after just one meeting, that's how floored he was by her. Photo: Getty

Rather than give Diana a family piece, Prince Charles bought her sapphire and diamond ring from royal jeweller House of Garrard. "There's a very famous sapphire brooch which Queen Elizabeth wears regularly, passed down from Queen Victoria. That was the inspiration for the sapphire engagement ring that the Duchess of Cambridge wears," they told MarieClaire.com during an exclusive interview. "Prince Charles had always seen this beautiful sapphire brooch of his mother's, which House of Garrard had created. When he went to House of Garrard he saw that ring, and thought it was perfect." Prince William eventually gave Diana's ring to his wife, Kate Middleton. Photo: Getty

The diamonds on Queen Elizabeth's platinum ring come from a tiara that belonged to Prince Philip's mother, Princess Alice of Battenberg. Apparently, Prince Philip was very invested in the ring's design, which is completely adorable. The Queen wears it to this day, paired with her Welsh gold wedding band. Photo: Getty

Lady Elizabeth Bowes-Lyon (also known as the Queen Mother) was given a sapphire and diamond ring by the Duke of York—which you can see in this sweet black and white photo taken at the time of her engagement. She eventually started wearing a pearl ring on her wedding finger, surrounded by diamonds. NB: It should be noted that sapphire and diamonds are something of a British royal tradition. See: Kate Middleton, Princess Diana, and Princess Anne. Photo: Getty