As reported by People, a new documentary for Curiosity Stream called Royals: Keeping the Crown looks into how Rainier and Kelly’s relationship began when the Principality of Monaco was in a rough spot financially and its royal family was in danger of losing their throne. Read on to see which Hollywood icon was considered for Rainier before he ended up with Kelly. RELATED: How Old 100 Iconic Stars Would Be If They Were Alive Today. According to the documentary, after World War 2, Monaco was not doing well financially and tourism needed to be upped as that was the principality’s biggest industry. The Chicago Tribune explains that Rainier was also at risk of losing his crown, because a 1918 treaty with France meant that if his bloodline ran out that Monaco would become a part of France. “Prince Rainier is now 32, and the idea that he might lose his principality if he doesn’t marry well and produce a male heir is uppermost in his mind,” Chandrika Kaul, PhD, a historian at the University of St. Andrews, says in the documentary. In order to bring attention to Monaco and help boost tourism, Rainier’s advisors thought he should marry an American actor. “Prince Rainier was advised that he would do well to marry a Hollywood ‘princess,’ and [capitalize on] all the celebrity and fame that went with that marriage,” Kaul explains. “What Monaco needed was to revive its tourism trade. It made perfect economic sense.” The documentary explains that Marilyn Monroe was the first suggestion for a Hollywood wife for the prince, but she didn’t end up making the cut. The reasoning, according to the documentary, was that she was too much of a sex symbol. To set the scene, at this time in the mid-1950s, Monroe was involved in other relationships anyway. She was married to Joe DiMaggio during most of 1954, and in 1956, she married Arthur Miller. For more celebrity news delivered right to your inbox, sign up for our daily newsletter. When Kelly was attending the 1955 Cannes Film Festival, she was invited by the magazine Paris Match to do a photoshoot in Monaco at the royal palace. “The executive[s] at Paris Match think that this will be a really dramatic, sensational meeting between the Queen of Hollywood and their own Prince, who is an eligible, young, handsome bachelor—who also just happens, rumor has it, to be looking for a wife,” Kaul says in the film. Royal historian Kate Williams explains, “During this photo shoot, you really see how Rainier is entranced by Grace, and really, I think, he falls in love with her on a personal level—but he also sees her as the answer to so many of his problems.” Kelly and Rainier got married on Apr. 19, 1956 in a wedding that was broadcast around the world. According to Rainier’s Chicago Tribune obituary, “tough bargaining ensued” between Rainier, Kelly, and her family prior to their engagement. Kelly underwent an examination from Rainier’s doctor to prove that she could have children, since Rainier was focused on having an heir. Rainier also asked Kelly’s father, who was a millionaire from the construction industry, for a $2 million dowry. When John Kelly “balked,” Kelly ended up paying half of it herself.ae0fcc31ae342fd3a1346ebb1f342fcb Rainier and Kelly were married until her death in 1982. Rainier never remarried and died in 2005. The couple welcomed three children during their marriage: Princess Caroline, Princess Stéphanie, and Prince Albert, who is the current monarch of Monaco. RELATED: See Elizabeth Taylor’s Lookalike Granddaughter, Who’s Carrying on Her Legacy.