Clementine, Lady Beit

There are as many reasons for liking a work of art as there are people to look at it. Even so, Clementine Beit's fondness for Goya's Portrait of Doña Antonia de Zarate was out of the ordinary. Gazing at the picture, Lady Beit would say, "That painting means a great deal to me for two reasons. Alfred was standing beneath it when he proposed to me, and we were tied up under it during the Dugdale raid."

It was, in various ways, an extraordinary thing to say. Alfred was Lady Beit's late husband, the second (and last) baronet. His uncle, the first Alfred Beit, had made a vast fortune through mining gold and diamonds in South Africa; together with the Wernhers and Oppenheimers, the Beits were the richest of the so-called Randlords, or goldbugs. The elder Beit used his money to amass one of the world's great private art collections, a treasure that included works by Hals, Velázquez, Rubens and Gainsborough, as well as the aforementioned Goya. Inheriting half of these pictures on his father's death in 1930, the young Alfred Beit bought a London mansion grand enough to house them - in Kensington Palace Gardens, known as Millionaires' Row - in 1937. The following year, after a short romance, he proposed to Clementine Freeman-Mitford beneath Goya's Portrait of Doña Antonia de Zarate: the painting under which the couple were to be tied up by robbers 35 years later.

Clementine Mitford was, like the Goya, something of a catch. The daughter of Major the Hon Clement Freeman-Mitford, she was born five months after her father's death in action on the Western Front in 1915. Her mother, a cousin of Clementine Churchill, prayed for a son: had her own Clemmie been a boy, she would have eventually succeeded her grandfather as the second Lord Redesdale. As it was, the title went to her father's younger brother, so that it was Clementine's cousins - Nancy, Diana and the rest - who became the famous Mitford Hons. Her own childhood was spent as a (relatively) poor relation, a situation that was put spectacularly to rights when, aged 23, she married the 36-year-old Conservative Member of Parliament for St Pancras in 1939.

The Beits weren't merely the richest young couple in London, they were also known as the handsomest. Two things blighted their glittering lives, however. The first was the revelation that they couldn't have children, the second the loss of Sir Alfred's seat - and his job as Parliamentary Private Secretary to the Secretary of State for the Colonies - in the 1945 Labour landslide. Furious at what they saw as the treachery of the British public and fearful of Clement Attlee's plans to tax the rich, the Beits set off for South Africa. Both were appalled by apartheid, however - "We madly disagreed with it" was Lady Beit's Mitfordian phrase - and hankered for London. The situation was made more complex when, in 1947, Sir Alfred's mother died and left him the rest of the family pictures. It was clear that Kensington Palace Gardens would no longer do; and it was while pondering what to do next that the Beits, paging through Country Life, saw an ad for an Irish house called Russborough and bought it by telegram in 1952.

Built in the 1740s, the Palladian Russborough was certainly big enough for the couple's pictures: its 700ft façade was the longest in Ireland. Its seclusion in the Wicklow Mountains also appealed to the Beits' taste for privacy, a reclusiveness that was to grow more pronounced as time went by. Unfortunately, the mansion's isolation was also attractive to art thieves, who realised that the nearest Gardai station was half an hour's drive away and that the frugal Beits would have skimped on security.

In 1974, an IRA gang led by a British heiress, Rose Dugdale, broke into the mansion at night, pistol-whipping the couple and leaving them bound and gagged under the fateful Goya. Or, rather, under what remained of it: the Beits had to look on as the raiders cut it and 18 other paintings out of their frames with a screwdriver. All these were later found in a cottage in Cork, and Dugdale was sent to jail. But 12 years later, in 1986, Doña Antonia was stolen again, this time by a notorious gangster called Martin Cahill who took other pictures including Lady Writing a Letter - the only Vermeer in private hands - and Gainsborough's lovely Madame Baccelli, already stolen by Dugdale. In June 2001, seven years after Sir Alfred's death, the Gainsborough suffered its third theft, this time at the hands of a gang that drove a Japanese 4x4 up Russborough's Palladian steps and through its (closed) front door. The widowed Lady Beit, now 85 and sitting down to lunch, was characteristically unruffled.

It was this, her implacable sang-froid, that made Clementine Beit what she was. A less assured woman might have tried to leave her mark on the Beit Collection and, in doing so, ruined it: Lady Beit, favouring modern Irish painters such as Jack Yeats and Derek Hill, kept her own modest acquisitions to herself. A less tenacious woman would have called it quits at Russborough after the first robbery, never mind the third: Clementine Beit stayed on to the end. And a more hot-headed woman might have railed at the Irish government, theoretically responsible for the collection's safety after Russborough's gift to the state in 1976.

Lady Beit did no such thing. As a result, the Beit Collection - lacking only Madame Baccelli and a Bellotto stolen in the final raid - will go to the people of Ireland, with Russborough to house it.

Charles Darwent