Remains of 8th century palace found on banks of Thames

THE remains of an Anglo-Saxon palace, which could be that of the powerful Mercian ruler Offa, have been discovered on the banks of the Thames.

Archaeologists found the wooden remains on the foreshore at Chelsea on a site now used as a mooring point for houseboats. Rachel Hill of the Environment Agency, which is funding the excavations, said that English Heritage had carbon-dated the timbers to the 8th century.

"We knew the timbers were old. There is documentary evidence that Offa had a palace around here and the dates just tie in," she said yesterday.

The discovery follows a series of other finds by the agency, including what is claimed to have been the jetty on the Thames where Sir Walter Raleigh laid down his cloak for Queen Elizabeth I.

However, the remains found at Chelsea are presenting the researchers with a serious conservation problem. Dr Hill said that the timbers' exposure meant that they were in danger of drying out and decaying. But under current laws they had no power to put a preservation order on them. The problem applies to all finds being made under the three-year Thames Archaeological Survey, ranging from Bronze Age and Tudor jetties to medieval fish traps. The archaeologists are trying to negotiate with the houseboat owners so that the boats are not moved on the low tide, which might damage the relics before the site has been fully excavated.

Sam Newton, an archaeologist and lecturer at the University of East Anglia, and authority on Beowulf, the Anglo-Saxon poem, said: "Offa was high King of all England, and London was an important place at that time. It is a fair presumption he had a palace there."

The find, made by the agency, University College London, English Heritage and the Museum of London, could be one of the most spectacular from this period. Remains of what is believed to be a royal palace from the first half of the seventh century have already been unearthed at Yeavering, Northumberland, and an important building from the sixth to the seventh century period found at Cowdrey's Down, Hampshire. But the discovery at Chelsea, made possible because it is one of the few areas left along the Thames in central London which has not been built over for flood defences, could rank as the most important.

Dr Hill said they were still busily documenting the finds, but they had found "50 metres of stakes, which were the line of defence, with the palace behind this".

Heinrich Härke, of the archaeology department at Reading University and an expert on the Anglo-Saxon period, said it was likely that the main palace would be about 27 metres long, built of timber and resembling a large barn. It was possible that there would have been a separate wing for women. "All the social life would go on around the fire. They would curl up and sleep around the fire," he said.

The discovery could shed new light on Offa, who ruledfrom AD 757 to AD 787 and was overlord of all England south of the Humber. He died in AD 796. The best surviving tribute to his power is Offa's Dyke, the earthworks along the Welsh border. During his reign, England achieved the greatest political unity that was seen during the Anglo-Saxon period. Dr Härke said that Offa was also responsible for introducing the silver penny, which boosted trade in the 8th century.