It might have been supposed that in Georgian England the age of miracles was passed. Yet at the very moment when Mrs Grockleton was chiding her husband for his lack of faith in Lymington - that is to say, at eleven o'clock that spring morning - a few miles away on the Beaulieu estate a miracle of sorts was in progress. It was happening at the busy place on the Beaulieu River known as Buckler's Hard.

There, in the bright morning sunlight, a man had become invisible.

The Hard - the name meant a sloping shore road where boats could be drawn up - had a lovely setting. As the river made a westward loop, broad banks created gentle slopes, almost two hundred yards long, down to the water. Situated some two miles downstream from the old abbey and the same distance upstream from the Solent water, it was a peaceful place, sheltered from the prevailing sea breezes. Once, long ago in the days of the monks, a furious prior with hands like claws had nearly come to blows with some fishermen at the river bend above. But his shouts had been one of the few to disturb the habitual silence of the sheltered curve and the reedy marshes opposite. The abbey had been dissolved, the monks departed; Armada, Civil War, Cromwell, the merry monarch, all had come and gone; but nobody had troubled about the quiet place. Until about seventy years earlier.

The reason was sugar.

Of all the opportunities for amassing wealth in the eighteenth century, nothing could approach the fortunes to be made in sugar. The sugar merchants' lobby in Parliament was powerful. The richest man in England, who had purchased a noble estate west of Sarum, was heir to a sugar fortune. The Morants who had bought Brockenhurst and other New Forest estates were a sugar dynasty, too.

The old Beaulieu Abbey lands had passed by marriage from the Wriothesley into the Montagu family and the Duke of Montagu, like many of England's great eighteenth-century aristocrats, was an entrepreneur. Although the ruined abbey was not a place where he spent much time, he knew that the Solent's double high tide, extending up Beaulieu river, made it apt for navigation and that he still possessed all the old abbey's river rights. 'If the crown will grant me a charter to found a settlement in the West Indies,' he decided, 'I could not only start a sugar plantation, but I could bring the sugar back to my own port at Beaulieu.' While the river banks were mostly mud, at the sheltered curve they were gravel, perfect for building upon. Soon a plan for a small but elegant harbour town had been prepared. 'We shall call it Montagu Town,' the duke declared.