Archaeologists say remains found near Stonehenge are almost certainly those of the ancient people who helped to build the monument.
Bluestone from Pembrokeshire was used at Stonehenge
Tests on teeth found in a 4,300-year-old grave at Boscombe Down suggest the prehistoric workmen were Welsh.
It was already known bluestone from the Preseli hills in Pembrokeshire were used in building Stonehenge - called Côr y Cewri which means Choir of Giants.
The grave was unusual as it contained the remains of seven people - three children, a teenager and three men.
Archaeologists are calling them "the Boscombe bowmen" because of the flint arrowheads in their graves.
Dr Andrew Fitzpatrick, of Wessex Archaeology, revealed the findings as the summer solstice dawned over Stonehenge.
"In medieval times, people believed that the stones could only have been brought to Stonehenge by Merlin the wizard," he said.
"For the first time we have found the mortal remains of one of the families who were almost certainly involved in this monumental task.
"The skulls of the men and the teenager are so similar that they must be related.
"The bowmens' teeth provided the clue to where they came from.
"As the enamel forms on children's' teeth, it locks in a chemical fingerprint of where they grew up."
Skulls were found in the 4,300-year-old grave at Boscombe Down
He said tests by British Geological Survey scientists on the bowmens' teeth showed they were raised in a place where the rocks are very radioactive.
"This was either in the Lake District or Wales," he said.
The grave was found during road improvement works.
Seven or eight pots were buried with the dead to hold food and drink for the journey to the next life.
The pots are very similar to those found nearby at a grave discovered last year containing a man known as the Amesbury archer.
He was the earliest metalworker known from Britain, and his grave contained the earliest gold objects in Britain.
Tests on his teeth showed that he came from central Europe.
Dr Fitzpatrick said: "The Boscombe bowmen, a band of brothers, must almost certainly be linked with the bringing of the bluestones to Stonehenge.
"With the discovery that the Amesbury archer came from central Europe, these finds are casting the first light on an extraordinary picture at the dawn of the metal age."
Dr Fitzpatrick will reveal more about the discovery on 23 June at 1305 BST in a talk at the National Museum & Gallery in Cardiff. The finds will be on display in Salisbury Museum from 3 July.