Monaco's Prince Rainier III has died after a battle with lung, heart and kidney problems, the palace said today. He was 81.
Rainier had ruled the tiny Mediterannean principality since 1949. He will be succeeded by 47-year-old Prince Albert, who took over his father's royal duties last week as hopes that Rainier would recover faded.
Renowned for his jet-set lifestyle, the 81-year-old succeeded his grandfather in 1949 and later had a whirlwind romance with Hollywood star Grace Kelly as she filmed Hitchcock's To Catch A Thiefwith Cary Grant along the mountain roads of the region's coastline.
The couple married in 1956, cementing Rainier 's status among Europe's glitterati. His new wife's celebrity helped to focus an unprecedented attention on the principality.
She became Princess Grace of Monaco and abruptly ended her acting career, a decision which at the time could have seemed plausible in only the most fanciful of her silver screen roles.
A year later their first child, Princess Caroline, was born. Prince Albert, the heir to the throne, followed 12 months after Caroline.
In 1962, Rainier set about building his legacy, overhauling the principality's constitution and authorising an ambitious construction project, which reclaimed a huge area of land from the sea and expanded Monaco's territory by 20%.
His proposals created shared power between the prince and an elected 18-member national council and abolished the principle of the divine right of the monarch.
The couple's third child, Stephanie, was born in 1965 and was badly injured in the car accident which killed her mother in 1982. Princess Grace is believed to have suffered a stroke while at the wheel on the region's mountain roads and lost control.
There were suggestions that Stephanie had been driving when the pair crashed, although these were discounted. Grace's death devastated the family and led Rainier to devote himself to attracting large businesses to the principality, hoping to lessen Monaco's reliance on tourism and the casino trade.
While his influence on the principality grew, the lifestyles of his children proved a troublesome distraction.
Princess Caroline, who inherited her mother's looks, was pictured topless as a teenager on a Mediterranean beach and went on to marry three times. Her first husband was French banker and playboy Philippe Junot. They married in 1978 and divorced two years later.
She married Italian industrialist Stefano Casiraghi in 1983 and they had three children, Andrea, Charlotte and Pierre, before his death in a power-boat racing accident in 1990.
In 1999, she married Prince Ernst August of Hanover and their daughter Alexandra was born later that year. In contrast, Rainier 's heir Prince Albert has yet to marry - a fact many commentators believe explains his father's decision to remain on the throne.
Now aged 47, Prince Albert has been linked to a succession of glamorous women including the German model Claudia Schiffer, but he has never settled down. He once said of his failure to find a wife: "I feel that the public should let me decide at my own pace."
After surviving the car crash, Princess Stephanie led an unconventional, and often wild, life. She had an affair with bodyguard Daniel Ducret and had two children - Louis and Pauline Grace - before they married in 1995.
The marriage ended when Ducret was caught frolicking with a Belgian stripper. Stephanie had a third child, Camille, in 1998, but refused to name the father.
Later, she took her children on the road with a travelling circus and in 2003 she married Adans Lopez Peres, an acrobat. In contrast to the lives of his children, Rainier 's formative years appear relatively staid.
Born on May 31, 1923, he was the son of Prince Pierre de Polignac, who adopted the name Grimaldi, and Princess Charlotte of Monaco.
He was was educated at St Leonards-on-Sea and Stowe in Britain, and later Switzerland and France, eventually reading politics in Paris. In 1944, the young prince enrolled as a volunteer in the French army and saw service in Alsace, winning the Croix de Guerre.
Rainier later served in the French mission in occupied Berlin and became a colonel.
Shortly after his return to Monaco, at the age of 26, his mother renounced her right to the throne and in November 1949 he succeeded his grandfather Prince Louis II as monarch of the principality, which is smaller than London's Hyde Park.
In 1993, Monaco celebrated one of its defining moments, as it became the 183rd member of the United Nations.
Four years later, during the 700th anniversary of the Grimaldi dynasty, Rainier said: "The prince must be able to act like a company chief when necessary, but must not allow his role as company chief to diminish his prerogatives as a prince."