The collection, put together at a cost to the dealers of £9,000, never left London. Instead, it remained the property of Desenfans and Sir Francis, who bequeathed the paintings to Dulwich College. On Sir Fran-cis's death in 1811, Dulwich Picture Gallery was founded as a permanent home for the collection. In short, the paintings never came into the possession of the Polish royal family. But, apparently straight-faced, the baron is demanding that the original deal should be honoured - more than 200 years after it was struck - and has offered £9,000 for the "return" of the priceless collection.