TWO major surprise discoveries lit up the final hours of Hyde900's Bank Holiday Weekend Community Dig to shed new light on the history of Hyde in Winchester and to solve a mystery linked to St. Bartholomew's church.

Excavations over three days in the back gardens of two houses in King Alfred Terrace covering what is believed to be the cloisters of Hyde Abbey had revealed a mass of building and other material dating back to the Middle Ages.

Hyde900 was set up to delve into the history of the abbey, the last resting place of King Alfred the Great.

However it wasn't until the final day that startling conclusions were reached which could transform understanding of this area of Winchester.

Potentially most important was the unearthing of a significant amount of Roman mortar fragments together with tesserae (small blocks of clay used in a plain mosaic floor) in one of the five trenches which had been opened up by the volunteer archaeologists.

Located at a level lower than that of an adjacent wall and floor – probably part of the medieval monastery - this prompted a re-evaluation of the site.

David Ashby, from Winchester University, said: “The volume of material that we have found opens out the possibility of a building from the Roman era in this location. The Roman road to Silchester ran about 100 metres to the west and it is possible that this material came from a nearby house in the countryside just to the north of the Roman city. But we had never seen this before.”

The discovery also suggested that maybe the cloister was deliberately built on an area where previous buildings could be used as a base, said Mr Ashby. In other parts of the abbey site it was necessary to import a 'raft' of clay to provide stability.

The second exciting discovery was of two Quarr stone 'abacus' fragments datable by their style to the first half of the 12th century. Originally thought to be plinths these were identified by Dr John Crook, consultant archaeologist to Winchester Cathedral, as being the load-bearing stones which are placed on the top of column capitals.

Measurements undertaken by Dr Crook showed that the abacus dimensions matched exactly those of the capitals which are now on display in St. Bartholomew's church and which have long been believed to come from the abbey cloister.

Dr Crook said: “The St. Bartholomew capitals are exquisite works of medieval art of international importance but until now we have only seen them in isolation. By discovering the two abacus fragments, however, we can now begin to visualise the capitals in context. We are developing a better idea of how they would have appeared in the medieval abbey.”

In total, five pits were dug over three days by 150 volunteers under the guidance of experienced supervisors from WARG, the society for local archaeology. Participants were of all ages from five years to 70. Many local primary school children were involved including, in particular, Year 5 pupils from the St Bede School who took part in Hyde900's first ever Archaeology day at the school.

David Spurling, the Hyde900 Trustee who oversaw the whole event, said: "It's been very gratifying to see the range of volunteers who have come forward both in terms of age and geography. As well as lots of local Winchester residents there were people from as far away as Dibden Purlieu and Surrey.”

Enthusiasm for the dig was wholesale from old and young alike. As one woman commented, “Thank you very much for a fascinating and enjoyable morning digging! My daughter and I really enjoyed ourselves - she especially enjoyed getting dirty! She has written up her experience for her Brownie Collector's badge. Many thanks, we'd definitely be up for it again!”

Among the many visitors to the dig were the Mayor Jane Rutter, and Parliamentary candidate Steve Brine along with Fiona Mather, a candidate for the County Council elections.

The open Visitors' Day on Sunday attracted a constant throughput of people observing the dig including several TV crews. “I would like to pay tribute to the support and tolerance of the householders – Chris and Anne Prior and Justine Field - who permitted us access to their gardens,” said Mr Spurling. “They have been quite remarkable.”

Justine was delighted by the experience. “This has been a dream come true for me,”she said.

Interest in exploring what lies beneath the surface of their gardens is now becoming infectious in Hyde. Already there are five more families volunteering their properties and Hyde900 is looking forward to further community digs next year.