text: Ronan Toolis led the excavation works at Trusty's Hill Fort at Gatehouse of Fleet.
  It unearthed evidence that it might have been the royal seat of the sixth century kingdom of Rheged.
  Mr Toolis said it was "pre-eminent among the kingdoms of the north" at that time.
  The location of Rheged had previously been thought by many historians to be in Cumbria.
  However, Dr Christopher Bowles, co-director of the excavation work in Dumfries and Galloway, said that may not have been the case.
  "The new archaeological evidence from Trusty's Hill enhances our perception of power, politics, economy and culture at a time when the foundations for the kingdoms of Scotland, England and Wales were being laid," he said.
  "The 2012 excavations show that Trusty's Hill was likely the royal seat of Rheged, a kingdom that had Galloway as its heartland.
  "This was a place of religious, cultural and political innovation whose contribution to culture in Scotland has perhaps not been given due recognition."
  Dr Bowles said the influence of the kingdom had "rippled through the history and literature of Scotland and beyond".
  Mr Toolis added that they had not been looking for Rheged when they started the excavations.
  "What drew us to Trusty's Hill were Pictish symbols carved on to bedrock here, which are unique in this region and far to the south of where Pictish carvings are normally found," said Mr Toolis.
  "The Galloway Picts Project was launched in 2012 to recover evidence for the archaeological context of these carvings.
  "But far from validating the existence of Galloway Picts, the archaeological context revealed by our excavation instead indicates the carvings relate to a royal stronghold and place of inauguration for the local Britons of Galloway around AD 600.
  "The new archaeological evidence suggests that Galloway may have been the heart of the lost Dark Age kingdom of Rheged, a kingdom that was in the late sixth century pre-eminent amongst the kingdoms of the north."
  The two men have produced a new book which details their findings.
  The Lost Dark Age Kingdom of Rheged is being launched in Gatehouse of Fleet on Saturday.
target: Archaeological research at a site in Galloway has suggested it may have been at the heart of a "lost kingdom" from the Dark Ages.