Prince Rainier III of Monaco was born 31 May 1923 in the Prince’s Palace of Monaco. He was the younger child and only son of Monégasque Hereditary Princess Charlotte, Duchess of Valentinois, and Prince Pierre de Polignac. The Prince was the first native-born Hereditary Prince of Monaco since Honore IV in the mid-1700s. He had one older sibling, Princess Antoinette, Baroness of Massy.
Prince Rainier’s mother, born illegitimate, was the only child of Prince Louis II of Monaco and Marie Juliette Louvet; Charlotte would be legitimised by way of adoption in 1919. Later, she was named heir presumptive to the throne of Monaco by her grandfather.
The early days of Rainier’s education were conducted in the United Kingdom at the prestigious public schools of Summerfields in St Leonards-on-Sea and Stowe School. After completing his schooling in the United Kingdom, Rainier attended the Institut Le Rosey in Switzerland beginning in 1939; his university education would take place at the University of Montpellier where he obtained a Bachelor of Arts degree in 1943. The Prince also studied in France at the Institut d’études Politiques de Paris.
At the age of 21, Rainier’s mother renounced her right to the Monégasque throne, making Rainier Prince Louis’s direct heir in 1944. When World War II began, Rainier decided to join the Free French Army, in September of 1944. The Prince served under General de Monsabet as a second lieutenant. For his service, he received the French Croix de Guerre with a bronze star; the latter represented a brigade level citation. Additionally, in 1947, Prince Rainier was given the rank of Chevalier in the French Legion of Honour. After being decommissioned from the French Army, the Prince was promoted to captain in April 1949 by the government of France; he would become a colonel in December 1954.
Prince Rainier came to the throne of Monaco on 9 May 1949 when he succeeded his grandfather, Prince Louis II. It was during a time which Monaco was near bankrupt, and it had started to lose its lustre through neglect and scandal.
As Rainier aged, he began to gain a reputation as a spoiled, playboy prince. Like many royal men before him, he was fond of fast cars and beautiful women. However, Rainier proved his detractors wrong when he set off to modernise the country. To do this, he received some help from the Greek shipping tycoon Aristotle Onassis.
Then, Rainier decided that the best way to bring Monaco back to glory was to promote Monaco as a tax haven and an international tourist attraction. He was even able to revive the Grand Prix de Monaco, which was one of the most prestigious automobile races in the world. So, by 1964, Rainier had regained control of the principality’s business dealings and had revived its commercial and real estate markets. By the mid-1960s, he and Onassis had parted ways.
The 1940s and 1950s saw Rainier have a ten-year relationship with the French film actress, Gisèle Pascal. He had met her while he had been a student at Montpellier University. Rainer and Gisèle Pascal lived as a couple at Saint-Jean-Cap-Ferrat. The relationship would later end after rumours were spread by Princess Antoinette that Gisèle was infertile, as well as snobby views being held about Gisèle’s family.
In the spring of 1955, American actress, Grace Kelly led the US delegation for the Cannes Film Festival and was invited to the Prince’s Palace of Monaco for a photo shoot with Prince Rainier. After meeting, they decided to share correspondence with each other for several months. He travelled to the United States in December 1955 as part of a tour. During that time, he met Grace’s family and proposed in her childhood home in Philadelphia.
They were civilly married on 18 April 1956 and religiously the next day in Saint Nicholas Cathedral. They had three children together: Princess Caroline (b. 1957), Prince Albert (b. 1958) and Princess Stéphanie (b. 1965).
In 1982, Princess Grace died from injuries sustained in a tragic car accident that was caused by her suffering a stroke.
Prince Rainier was a heavy smoker who smoked up to 60 cigarettes a day; in the final years of his life, his health began to significantly decline. He underwent surgeries late in 1999 and 2000, and he would be hospitalised many times in the future. He was hospitalised for the final time in early March 2005 and was put on a ventilator on 23 March after being admitted to the intensive care the day before.
Prince Rainier passed away in the early morning of 6 April 2005 at the Cardiothoracic Center of Monaco at 81-years-old. Rainier and Grace’s only son, Prince Albert, had been named as regent on 31 March after discussions with the Crown Council of Monaco. On 15 April 2005, Prince Rainier was laid to rest beside Princess Grace at the Saint Nicholas Cathedral.