Lucy chose her own engagement ring, a cushion-cut diamond on a thin gold band, for her marriage to Desi Arnaz.
The diamond on Queen Elizabeth II's engagement ring came from a tiara owned by Prince Phillip's mother, Princess Alice of Battenberg.
John F. Kennedy gave Jacqueline Bouvier a custom Van Cleef & Arpels engagement ring featuring a 2.84 carat emerald and a 2.88 carat diamond.
Joe Dimaggio gave this eternity band, set with 35 baguette-cut diamonds, to Marilyn Monroe at their 1954 wedding.
Princess Grace originally received a Cartier eternity band (left) comprised of rubies and diamonds from Prince Rainier III of Monaco, but he soon swapped it for a 10.5-carat Cartier diamond ring.
Taylor's third husband, Mike Todd, gave her this "friendship ring" of 29 karats before their 1957 wedding.
Robert Wagner hid Wood's ring, a freshwater pearl surrounded by diamonds, in her champagne glass at Romanoff's restaurant on Rodeo Drive when he proposed in December of 1957.
Frank Sinatra gave Farrow a pear-shaped solitaire diamond ring before their July 1966 wedding.
In 1968 (four years into their first marriage), Richard Burton gave Elizabeth Taylor the Krupp Diamond, a 33.19-carat Asscher-cut jewel. Though not technically an engagement ring, it's one of the most iconic pieces of jewelry of all time.
When Lady Diana Spencer and Prince Charles became engaged in February 1981, Diana chose a Garrard ring with a 12-carat oval sapphire surrounded by 14 solitaire diamonds.
Matthew Broderick gave SJP her stunning emerald-cut ring before the couple's 1997 marriage.
Will Smith proposed to Jada Pinkett with this emerald-cut diamond in 1997.
David Beckham proposed to Victoria Adams with a three-carat marquise-cut diamond.
For his 2004 engagement to Garner, Ben Affleck selected a 4.5-carat diamond solitaire ring set in platinum from Harry Winston.
Jay Z gave Beyoncé a $5 million, 18-carat Lorraine Schwartz diamond in April 2008.
King's beau, director Kyle Newman, presented her with a pavé-set solitaire diamond in April 2007.
Tom Brady gave Gisele a four-carat diamond solitaire ring when they became engaged in late 2008. The couple married during a private ceremony in February 2009.
Francois-Henri Pinault presented Hayek with an oval-shaped diamond ring from Neil Lane before the couple wed on Valentine's Day in 2009.
Blunt's three-carat diamond-and-platinum ring from husband John Krasinski was custom-made by Neil Lane.
Prince William gave Kate Middleton the famous sapphire-and-diamond ring that belonged to his mother, Princess Diana.
From Elizabeth Taylor's 33-carat rock to Catherine, Duchess of Cambridge's heirloom sapphire, the celebrity engagement ring is an object of constant fascination. Here, we trace the most iconic, from Hollywood's Golden Age to today.