His was a life that saw the heights of fame and fortune and the depths of personal tragedy, but through it all, his Serene Highness, Prince Rainier II of Monaco endured.

Born in 1923, Rainier was on the throne since 1949, making him the longest reigning monarch in Europe.

For over five decades he managed to maintain a magical, fairy-tale-like atmosphere in his tiny kingdom high atop the cliffs of the sunny Côte D'Azur.

Much of that Mediterranean magic, of course, came not from Rainier, but from Grace Kelly, the woman he married in 1956.

When Rainier met Kelly at the Cannes Film Festival, during a photo session arranged by Paris Match in 1955, the sparks flew and an enduring romantic legend was born.

Kelly was a Hollywood actress at the top of her game, celebrated for her regal good looks and for her acclaimed acting ability.

By 1953 at the age of 24, she'd already been nominated for Best Supporting Actress for her role in Mogambo. Two years later in 1955, she won the Best Actress Oscar for the film, The Country Girl .

But by 1956, Kelly turned her back on Hollywood when she married Rainier and retired from acting for good. That same year saw the release of her last film, the musical High Society .

Ironically, a chief concern for Rainier was keeping his own high society alive.

He'd been on the throne seven years and needed a wife in order to have children and ensure the future viability of his principality -- and his Grimaldi dynasty which traces its origins in the kingdom back to 1297.

There had been concern that, were Rainier to die without an heir, Monaco would revert back to French control.

The wedding in 1956 was designed to put those fears to rest.

And, by all accounts, it was a great match, a part that Kelly seemed born to play.

Glittering wedding

The glittering, Catholic nuptials made headlines around the world, and shortly after Prince Rainier and the newly-titled Princess Grace, settled in to their new family life.

Grace gave birth to three children, starting with Princess Caroline, in 1957, followed by Prince Albert, the heir to the throne, in 1958. Seven years later, their third child, Princess Stephanie, was born in 1965.

As the new Grimaldi family grew and put down roots, so did the reputation and respect for their kingdom.

It was a change of stature for Monaco that was badly needed.

From the 1920s on, the kingdom had earned a reputation, as British writer Somerset Maugham once quipped, as "a sunny place for shady people" - a popular place for the rich and famous to gamble, drink champagne, dock their yachts and bask in the sun.

With Grace on his arm, Rainier managed to improve Monaco's image, attracting more business and investment.

The fairy tale seemed complete: a prosperous kingdom, a popular leader, and a happy family.

And then tragedy struck.

Grace dies at 52

Grace died in a freak car accident in the hills above her home in 1982. She reportedly suffered a stroke while at the wheel and lost control. Princess Stephanie, a passenger in the car, was badly injured.

Monaco was first hit by a wave of shock, then disbelief and then profound grief. Grace had been much more than popular royal icon, she'd been universally loved.

Her husband and family never seemed to be the same after her death.

While Rainier himself continued to work hard to shore up Monaco's business dealings, his family seemed to attract unwanted media attention for their sometimes stormy, sometimes tragic personal lives.

Caroline overcame the disgrace of a short-lived marriage to playboy Phillipe Junot in 1978 to find happiness with Italian, Stefano Casiraghi in 1983. He, however, was tragically killed in a speed boat racing accident in 1990.

She has since remarried a German prince.

Albert, meanwhile, has never married and details of his private life have remained largely out of the public eye. Instead, he is best known for his business acumen and economic endeavours.

Monaco changed its succession law in 2002 so that Albert can pass the throne to someone other than his own child, if he has no children by the time he dies. Under the revised law, power eventually could be passed from Albert to his siblings or their children.

Stephanie, meanwhile, has gained a reputation as the wild child of the Grimaldi household.

Her personal life, which has been fodder for the tabloids for years, include her marriage to her bodyguard after having two children out of wedlock with him. They married in 1994, but divorced soon after.

Other romances -- and another child born out of wedlock to an unidentified man -- ensued before her marriage in 2003 to a circus performer in Switzerland.

Many see Rainier's death as the final chapter in a fairy-tale romance -- one that began over half a century ago when a European prince claimed the hand of an American movie queen.

Even today, decades after the tragic death of Rainier's beloved Princess Grace, the flames of their romance continue to burn bright, captivating the world.