Conservationists have employed scientific techniques designed to treat the timbers of sunken galleons to preserve the Cosimo Panel, the most delicate and intricate work of Grinling Gibbons, probably the world's greatest decorative wood carver.
During the past three centuries the panel has survived fire, flood and neglect and an attack of woodworm.
Gibbons was commissioned by Charles II to make the carving as a present given in 1682 to the Grand Duke of Tuscany, Cosimo III de Medici. However, it soon became lost in obscurity and was only re-identified as the Cosimo Panel in the 1960s.
The Florence flood of 1966 engulfed the panel in mud for a week and despite being skilfully restored it was badly burnt in 1984 by a fireball from a gas explosion in Florence's Pitti Palace.
Conservators treated the carving with a preservative specially developed by marine archaeologists so that the panel could make the 750-mile return journey to London, where it will be the star attraction of a Grinling Gibbons exhibition at the Victoria & Albert Museum later this month.
Cracks that appeared after the panel was soaked in the flood and the charred edges of the most delicate areas of the woodwork made the carving vulnerable to damage during the road journey from Italy.
David Luard, a conservator working for the V&A, coated the most singed edges of the carving with a protective substance designed to act as a mild glue. The panel arrived last week unscathed from its overland trip.
The panel, carved from three and sometimes four layers of limewood, measures just over 3ft 3in by 5ft 2in and is famous for its spectacular cascades of lifelike flowers, fruits and leaves.
Woodcarving experts had once believed that the techniques used by Gibbons to create the illusion of real objects, such as feathers and leaves emerging from the carving, had been lost. However, another work of Gibbons that had been damaged in the Hampton Court fire of 1986 gave restorers an unprecedented chance to discover the secret of how he constructed his carvings in separate layers.
The exhibition, which is being sponsored by GlaxoWellcome, the drugs company, will demonstrate for the first time how Gibbons created his three- dimensional effect with the aid of views of the limewood layers he glued or nailed together.
Among the other works on display at the exhibition, being held on the 350th anniversary of the woodcarver's birth, will be the mantel from Badminton House and the canopy from the bishop's throne in St Paul's cathedral.