THE love affair between the notorious Princess Pauline Borghese, Napoleon's favourite sister, and Alexander, the 10th Duke of Hamilton, is an obscure story which has remained largely untold.

But now it is being introduced to young people by the Royal Museum in Edinburgh through a tour focusing on the travelling service the princess left the Duke of Hamilton, known as El Magnifico, in her will.

As exquisite as the travelling service items undoubtedly are - a gold embossed chocolate pot, dressing table items inlaid with mother-of-pearl, engraved candlesticks and writing materials, all designed by Martin-Guillaume Biennais, Napoleon's official goldsmith - the characters involved are the real story.

As Napoleon rose to power, his four brothers and three sisters were used as pawns to form strategic alliances to further his meteoric career and stabilise the new regime.

Pauline,12 years younger than Napoleon, hero-worshiped her brother and was to prove her loyalty by staying with him for a time when he was exiled to Elba.

However, before then Pauline, who bore a remarkable resemblance to Napoleon, was to live a scandalous life which made her brother furious.

In 1797, when she was 17, Napoleon thought he had solved the ''Pauline business'' by marrying her off to the ambitious General Victor Leclerc. They had a son, Dermid, but motherhood did not engage Pauline.

With Leclerc on manoeuvres, Pauline's behaviour riveted Paris. She began relationships with three generals at the one time. Spoilt for choice she played one off against the other.

Eventually the three, who were close friends, nominated the most senior to hand in a ''resignation'' letter on their behalf. Undeterred, Pauline posed naked as Venus for a series of marble statues by Antonio Canova.

Napoleon acted swiftly and ordered Pauline to accompany Leclerc to San Domingo to restore French rule. A year later Leclerc died from yellow fever.

Pauline's second marriage the following year to Prince Camillo Borghese, head of one of the greatest Italian families, soon ran into trouble and the prince retreated to Italy. When Dermid died a year later, Pauline was again adrift without an anchor.

Among those who attracted Princess Pauline's attention was the 6ft 2in heir to Hamilton Palace. Alexander was a wild and debonair figure who believed he was the true heir to the Scottish throne. An ardent Bonapartist, Alexander was 13 years older than Princess Pauline and had been sent as British ambassador to the court of St Petersburg. He was also married with two children.

In 1819, Alexander succeeded his father as the premier peer of Scotland and hereditary keeper of Holyrood House.

Lord James Douglas Hamilton, MSP, and a relative of the 10th Duke, said it was ironic that, at a time of great strife in Europe, he had had time to have a relationship with Napoleon's sister.