Prince Albert, the 52-year-old ruler of the tiny state of Monaco, who announced his engagement on Wednesday to Charlene Wittstock, has for years been one of the world's most eligible bachelors.

Prince Albert took over the reins in the Mediterranean statelet wedged between the Alps and the sea after the death of his father Prince Rainier in April 2005.

Often seen in public, at openings and sports events, Prince Albert has earned a reputation as pleasant and laid-back among Monaco's population of 32,000, and is seen as more accessible and less autocratic than his father.

With a fortune estimated at some €2 billion, Prince Albert has been seen with a string of beautiful women over the years.

But he has managed to keep his love-life largely out of the public view - in contrast with his sisters Caroline and Stephanie whose stormy affairs have been a constant source of celebrity gossip.

He has fathered two children, a girl and a boy who were officially recognised after he had acceded to the throne, but neither can succeed him as Monaco's constitution requires its rulers to be born in wedlock.

The children are Jazmin Grace, 20, whose mother Tamara Rotolo is a former American waitress and Alexandre Coste, six, from a French-Togolese former flight attendant, Nicole Coste.

His engagement to Ms Wittstock had been widely anticipated, after the swimming champion was photographed on the prince's arm at a number of functions in Monaco, a Riviera millionaire's playground.

Prince Albert's failure to marry and have legitimate children had resulted in a 2002 change to Monaco's Constitution, under which the 700-year-old Grimaldi dynasty can continue through the female line if he dies without an heir.

"I have enjoyed this prolonged celibacy which gives me a certain freedom. But, be assured, I will marry," he said in November 2005.

Meanwhile, News of Prince Albert II of Monaco's engagement to the swimming champion was splashed across front pages in her native South Africa, with news media anticipating a "fairytale wedding".

"A South African beauty has bagged a Prince, one of Europe's most eligible bachelors," said The Times.

"Fairytale wedding for playboy Prince, Benoni (South Africa) swimmer," said The Star, one of several dailies to run a large photo of the couple on its front page.