Lucky Princess Diana, she got to choose her own ring from a selection presented by Garrard Jewelers when Prince Charles proposed. There are a few different theories on why Diana selected the 18-carat oval sapphire surrounded by 14 diamonds: the color matched her eyes, the Queen may have actually selected it, or as Diana was later quoted as saying, "It was the biggest."
The Duchess of Windsor
Fitting to the epic love story of Wallis Simpson, the Duchess of Windsor, and Edward VIII, who abdicated his throne for her, the 19.77 carat emerald engagement ring bore a personal inscription. It read: "We are ours now 27 X 36." That's shorthand for the day Edward proposed, October 27, 1936.
The Duchess of York
After Prince Andrew proposed to Sarah Ferguson with a ruby from Garrard Jewelers, it set off demand for ruby engagement rings in England. It is said he chose the unusual color because it matched his betrothed's fiery red hair.
Prince Rainier III of Monaco originally proposed to Grace Kelly with a Cartier eternity band of rubies and diamonds. When he saw other leading ladies in Hollywood were flashing bigger rings, he quickly ordered this 10.5-carat emerald-cut diamond flanked by two baguettes, also from Cartier.
Queen Elizabeth II
The diamonds for Queen Elizabeth II's engagement ring from Prince Philip have a special history: They came from a tiara belonging to Philip's mother, Princess Andrew of Greece.
Marie Chantal Miller, Crown Princess of Greece
When Crown Prince Pavlos of Greece proposed to Marie-Chantal Miller, reportedly on a ski lift in Switzerland, it was with this ring featuring a family heirloom sapphire and a heart-cut diamond that was his personal touch.
Sophie, Countess of Wessex
Following in family tradition, Prince Edward also proposed with a ring from the British royal jeweler Garrard. He presented his bride Sophie Rhys-Jones with a two carat oval diamond, flanked by two smaller heart-shaped gems—the ring is worth an estimated $150,000!
Prince William presented Kate Middleton with his mother's Garrard Jewelers sapphire ring.