Archaeologists have discovered an ancient fort which sheds new light on how the Romans dealt with resistance to their rule.

Excavations at Alchester, south of Bicester, have revealed a fort, which is the earliest-known example of a wooden Roman construction in Britain.

The fort also includes what is believed to be the first artificial, flowing water supply in the country.

Archaeologists discovered the fort three years ago using aerial photographs taken of the area.

The high water table at the fort preserved its gatepost timbers, allowing scientists to place the date of the fort's construction at the autumn of AD44, using tree ring dating.

This was just one year after the Romans, under the Emperor Claudius, landed on the south coast. The excavation, by the University of Leicester, is being led by Dr Eberhard Sauer, who said: "Now we know that, already in the second year of the war, Roman control over the Midlands was firm enough for the Army to build a permanent base in Oxfordshire."

The 22-acre fort consisted of a rampart, surrounded by two water-filled ditches, within which there were barracks, a workshop and a courtyard. A training ground and marching camp for soldiers have also been found nearby.

Archaeologists believe that the fort was used for between ten and 20 years, after which the garrison was moved closer to the Romans' new frontiers in the north of England and Wales.