Political boundaries are as old as the Bronze Age

It is a political divide that three millennia of Britain's turbulent history has failed to erase. Archaeologists have found evidence that the parish boundary line between the villages of Ashton Keynes and Somerford Keynes on the Wiltshire-Gloucestershire border may have been drawn in the Bronze Age, writes Steve Farrar.

If the research by a team from the Oxford Archaeological Unit is confirmed, it would make it the oldest political division yet discovered in the United Kingdom.

The archaeologists uncovered a 200 metre straight line of pits this summer that matches the current border between the two parishes, and, coincidentally, the counties as well. Similar alignments discovered elsewhere in the country have never been associated with a modern frontier.

Gill Hey, who led the excavation, said the simple open pits were unlikely to have presented a physical barrier but may have been symbolic and could have been emphasised by a hedgerow. The barrier may have held some kind of ritual importance.

But its survival suggests it was respected and upheld nonetheless for more than 3,000 years. "It's hard to physically prove they are the same boundary but it is a remarkable coincidence as the two lines are within feet of each other and are on exactly the same alignment," said Ms Hey. "We were very surprised to find it - I don't know of anyone else who has found a line like this with links going back so far."

The evidence suggests the boundary was established in the late Bronze Age, when permanent settlements were being set up and land was being divided by farmers and tribes for the first time.

There are no physical features such as rivers, streams or hills that could dictate the Ashton Keynes-Somerford Keynes line, hinting that it may have been among Britain's first artificial boundaries.

It then survived subsequent invasion and migration, including the influx of Celtic tribes, Romans - whose field patterns recognised the line - Saxons and Normans. There are many parish boundaries today that were laid out more than 1,000 years ago and a number that are known to follow Roman land divisions.