Prince Rainier III of Monaco

Europe's longest-reigning monarch

Whatever else may be said about Rainier III, Sovereign Prince of Monaco and holder of a score of other titles beside, one thing cannot be denied: he gave it his best shot. During a reign of almost 56 years - he was, after King Bhumibol Adulyadej of Thailand, the world's second longest-reigning monarch - he never ceased his efforts to diversify and strengthen his tiny kingdom's economy, to improve its image, and to ensure a smooth succession. By the end, however, his achievements were threatened on all three of those fronts.

Rainier Louis Henri Maxence Bertrand de Grimaldi, Prince of Monaco: born Monaco 31 May 1923; succeeded 1949 as Prince Rainier III of Monaco; married 1956 Grace Kelly (died 1982; one son, two daughters); died Monaco 6 April 2005.

Whatever else may be said about Rainier III, Sovereign Prince of Monaco and holder of a score of other titles beside, one thing cannot be denied: he gave it his best shot. During a reign of almost 56 years - he was, after King Bhumibol Adulyadej of Thailand, the world's second longest-reigning monarch - he never ceased his efforts to diversify and strengthen his tiny kingdom's economy, to improve its image, and to ensure a smooth succession. By the end, however, his achievements were threatened on all three of those fronts.

Rainier rode, but could not tame, the tiger of celebrity. Try as he might, he could not give his kingdom a life and identity separate from the family which reigned over it. The watershed of his reign was not a political event but a personal tragedy: the death of his wife Princess Grace, the former film actress Grace Kelly, in a motor accident in 1982. Until then, Monaco had gleamed with the reflected glory of its ruling couple. Thereafter it floundered amid the tabloid antics of their children.

Rainier Louis Henri Maxence Bertrand Grimaldi was born in 1923, the second child of Pierre, Comte de Polignac, and Charlotte, the lovechild of Louis Grimaldi, who ruled Monaco from 1922 to 1949, and an Algerian laundrymaid called Marie Juliette Louvet. His own parents divorced when he was six, and the young Rainier was sent to school in England, first to Summerfields near Hastings ("a horrible place", he remembered, "short pants, cold showers and canings") and then to Stowe, which he hated so much that he ran away.

After barely a year, he was moved to more congenial Switzerland and boarding school at Le Roset near Gstaad. Thereafter he studied at Montpellier and in Paris, but the combination of English schools and an English nanny ensured that, to the end of his life, Rainier spoke French with the tinge of an English accent. Otherwise, his sole acquisition from the Spartan rigours of life outre-Manche was - oddly for a shy and retiring boy - a decent skill at boxing.

By now Europe was plunged in conflict. The Second World War, when the principality was first co-opted by the Italians, and then became an R&R centre for German troops and money- laundering conduit for Nazi notables, was not Monaco's finest hour. But it was when Rainier came of age, in every sense.

Three months after his 21st birthday, he enlisted as a foreign volunteer in the French army and fought in the campaign to liberate Alsace, where he was decorated for bravery under fire. Rainier was promoted to first lieutenant and, after the defeat of Nazi Germany, served for 17 months at the French military mission in Berlin. But, if the world was changing, Monaco was not. When Rainier returned home in 1946 he found his ailing grandfather Louis interested not in affairs of state but exclusively in the French actress Ghislaine Marie Dommanget, his long-time mistress, now his wife. Frustrated, he moved out and took a villa at St Jean-Cap Ferrat, five miles down the coast.

Then, on 9 May 1949, Louis II died, and Rainier became the 33rd ruler of the Grimaldi dynasty, descended from a family of Genoese adventurers which seized Monaco in 1297. Outwardly his inheritance, a square mile of territory tucked between the French Alps and the Mediterranean, seemed the opulent candyfloss kingdom of always. But the tranquillity was deceptive.

Somerset Maugham once famously described Monaco as "a sunny place for shady people". Nearer the mark was a French newspaper which in 1929 likened the place to "a box of toys in which everything is brilliant and artificial and a little fragile, and must be kept carefully fitted into its place if it is not to be broken". In fact, resentment at the vast power of the Société des Bains de Mer (SBM) which ran the casinos was rife, and at one point Louis was hard pressed to resist calls for Monaco to become a republic.

But, under Rainier, the kingdom's image would be transformed. He might have been reserved and shy, but his gift for public relations was unmatched. Instinctively, he understood the fascination royalty exercised - particularly a royal prince who for the first post-war decade was considered the world's most eligible bachelor.

Not that he was unattached. A six-year romance with Gisèle Pascal, a French actress, only ended in 1953; when it did, Rainier took himself off on a long boat trip to West Africa, returning with enough animals to found Monaco's zoo. Throughout his life, animals, and cars (of which he owned 45 in the late 1980s) would remain absorbing interests.

Then, in April 1956, came his supreme publicity coup: marriage with a Hollywood star who looked more like a princess than any real princess on earth. Rainier had met Grace Kelly when she visited Monaco during the 1955 Cannes Film Festival. It was an intense courtship, albeit one conducted in large part by correspondence. That Christmas Rainier was in Philadelphia, staying at the Kelly family home, where he proposed (accompanied, it is said, by a doctor who carried out fertility tests to ensure Grace could provide an heir).

The engagement was a global sensation. The wedding, which was held in Monaco's cathedral, coincided with the launch of Eurovision and was watched by more people than any previous event in history. Some 1,600 reporters and photographers were in attendance - more, it was noted, than covered the entire European theatre during the Second World War.

The world feasted on the fairy tale, and the fairy tale, miraculously, endured. Barely nine months after the marriage, Rainier's first child, Caroline, was born. Cool and regal, yet loving and motherly, Grace was a perfect first lady, setting up charities, founding a hospital and an academy of classical dance. Monaco was the hottest princedom on the planet, louche no longer but dripping glamorous respectability from its every gold-plated tap.

Rainier's other strategies to attract money and attention to Monaco succeeded scarcely less well. A feud with Charles de Gaulle that had the general threatening to "asphyxiate" the principality in order to stamp out French tax evasion earned Rainier much sympathy. Three years later, in 1965, he cocked another snook at the neighbouring Goliath by allowing US vessels to use Monaco's port after de Gaulle closed American bases in France and pulled out of Nato's military structure.

He also engaged in a famous dispute with Aristotle Onassis over SBM, which the Greek magnate had surreptitiously acquired a few years before. Rainier, unhappy at Onassis's plans to split the company up, brilliantly outmanoeuvred him by issuing new shares which nationalised the company, and then buying Onassis out for half the price the Greek expected. "He screwed de Gaulle and he screwed Onassis" was the crude but accurate tribute to Rainier's nerve and negotiating skills. Gradually he shifted the economy away from its reliance on casino income, establishing Monte Carlo as a convention centre, and a site for light, non-polluting industry.

In private, the idyll might have been fading, as Grace, finding Monaco increasingly dull and constrictive and missing her Hollywood friends, spent more and more time in Paris. Caroline too would later remember her father during her childhood as frequently distant, reproachful and unaffectionate. But, in public, the Grimaldis of Monaco seemed sprinkled with stardust.

The high point of his reign was surely the picnic to which he invited all 4,500 of his subjects in May 1974, to celebrate the 25th anniversary of his accession. Rainier was a prince with a perfect princess and three handsome children, presiding over an earthly paradise, his people immune from the oil upheavals that were sending shock waves through the world economy.

Every fairy tale comes to an end. The Grimaldis' time of troubles started in earnest in 1978. Beautiful young princesses are beloved by paparazzi at any time, but Caroline had already achieved the distinction of becoming the first European princess to be photographed topless. She carried rebellion further by marrying, against her parents' wishes, a French playboy, Philippe Junot. The union lasted but two years, destroyed by Junot's philandering.

That setback however was nothing as to what happened on 14 September 1982. Rainier and Grace might have been tiring of each other, but her death in a car accident was a shattering blow, and one not lessened by persistent rumours that 17-year-old Stephanie, their tearaway youngest daughter, and not Grace, might have been at the wheel of the Rover 3500 when it plunged off the Moyenne Corniche on the way down into Monaco.

The tragedy only intensified media interest in the children, and the media were not disappointed. In 1983 Caroline married a wealthy Italian industrialist, Stefano Casiraghi. But his death in a powerboat accident in 1990 left her a widow with three young children under six and underscored the seeming curse that hung over the house of Grimaldi. Stephanie meanwhile kept the celebrity magazines humming with her adventures, including three children out of wedlock, a predilection for bodyguards from the wrong side of the street, and a fondness for displaying tattoos on her derrière.

Then there was the failure of Albert to find a bride, despite road-testing the finest of European womanhood. Some began to wonder aloud, was the crown prince gay? In 2002, Rainier would change the constitution so that his daughters might inherit and the Grimaldi dynasty's future be secured.

In 1994 came the embarrassment of Robert Lacey's biography Grace. According to the British writer, Rainier's dead wife had had countless torrid affairs before she married him, and later forlornly consoled herself in Paris with a succession of young lovers as her husband took mistresses of his own. Rainier branded the book "dirty and untrue" and threatened legal action.

The toll on Rainier was steadily more visible. Increasingly his children, for all their peccadilloes, helped with his official duties. The prince spent ever more of his time at his farm at Roc Agel in the hills behind Monaco, surrounded by silver-framed photos of Grace. Had Albert settled down, or even earned his father's full confidence, Rainier almost certainly would have abdicated by the early 1990s. But he soldiered on, defending his achievements in a newspaper interview in May 1999 to mark the 50th anniversary of his accession. He had, he insisted, restored the principality's economy and finances: "That is the reality of Monaco, not the deformed image that some like to present." And, for all the tabloid scandals, the day-trippers and tourist buses that lowered the tone, the principality's celebrity-studded population of 35,000 had few complaints about their lot.

Even Rainier's feckless children seemed to be calming down. Caroline married for a third time, to the German prince Ernst August of Hanover, and her eldest child, her 20-year-old son Andrea, now looks a plausible successor to the throne. The once untameable Stephanie, having dallied - after the breakdown of her first marriage to one of those royal bodyguards - with actors, palace servants, a circus owner and a Manchester United goalkeeper, married for a second time, to an acrobat, in 2003, albeit the marriage lasted only 10 months.

Other clouds, however, were gathering over Monaco. Disputes with France persisted over questions of VAT and accusations of money-laundering. The principality's position as a participant in the EU (it joined the euro in 2002) without being a member of it seems increasingly awkward. The death in 1999 of the banker Edmond Safra in his heavily protected apartment fanned fears that the Russian mafia was imposing its ways on a principality that previously hadn't had a murder in decades. In fact, Safra was killed by a fire started by his male nurse, but the episode was a sign of a changing and edgier Monaco.

By the end, Rainier must have realised that, for all his efforts, the magic kingdom by the sea could not escape the realities of the world around it.

Rupert Cornwell