Rainier oversaw great change in Monaco
Rainier III ruled a playground for the super-rich. Monaco's glamorous reputation was boosted by the staging of a Formula One Grand Prix on the capital's streets, and by the prince's marriage to the film star Grace Kelly.
Rainier was head of one of the oldest reigning dynasties in Europe and ruler of a state which, with its reputation as a gambler's paradise, Somerset Maugham once described as "a sunny place for shady people".
He had met his wife-to-be at the Cannes Film Festival in 1955. Their wedding the following year captivated the world.
Held onto power
He was the epitome of Prince Charming, she the glamorous Hollywood actress at the height of her popularity. The fairy tale lasted until her death in a car crash in 1982. He never re-married.
Rainier's marriage to Grace Kelly captivated the world
A descendant of the Genoese House of Grimaldi, Rainier first went to school in Britain, then Switzerland and finally attended university in France where he studied political science.
In June 1944, the now heir to the succession became second-lieutenant Grimaldi in the First Algerian Regiment of the First French Army and went through the winter campaign in Alsace.
In 1945 he received the Croix de Guerre for carrying out liaison duties under enemy fire. Two years later he was awarded the Legion of Honour with bronze star for his military service.
When he inherited the throne of Monaco in 1949, he inherited with it absolute power and was never afraid to defend the rights of his 800-year-old dynasty.
Threat from Onassis
When, in 1958, Monaco's parliament, the National Council, sought constitutional reforms to have a greater say in state affairs, he made it clear that he would tolerate no attempts to curtail his powers.
The conflict came to a head the following year over the budget. The Prince suspended the constitution, thereby dissolving the National Council.
Later he announced the appointment by decree of a national assembly chosen from among "a wide range" of Monegasque circles, who would act in the same capacity as the former National Council.
Monaco became the playground of the super-rich
There was another attempt to curb his powers in 1962 when General de Gaulle tried to bring Monaco under French tax law. Rainier saw off the threat.
Then, in the mid-1960s, the Prince prevented an attempt by the Greek shipping owner Aristotle Onassis to buy his country's most famous institution, the casino.
The people's affection
Prince Rainier changed the law so that the casino was allowed to generate no more than 4.5% of state income.
Aware that his country had no natural resources, he used his contacts and business acumen to improve modern light industry and develop his country as a tourist resort tax-haven for the wealthy, and a fashionable centre for business conventions.
He put in place measures to put Monaco on a sound financial footing.
Rainier with his daughters Caroline and Stephanie
If the obsession of the world's gossip columns with the eventful private lives of his daughters Caroline and Stephanie hurt him, the Prince never showed it in public. His dignity did much to preserve his family's image.
Prince Rainier leaves his son, Prince Albert, a principality that may face uncertain times ahead economically, but a throne which is secure in the affections of his people.