STONEHENGE was built by a Welsh family, archaeologists now believe.
The discovery of an early Bronze Age grave, made by workmen laying pipes on Salisbury Plain, is further proof that England's ancient landmark is a Welsh export.
Chemical tests on the 4,300-year-old teeth of seven people unearthed on Boscombe Down, Wiltshire, show they came from South West Wales or the Lake District.
But because the stones are bluestone brought from the Preseli mountains in Pembrokeshire, experts say the remains almost certainly belong to people born in Wales, who were among Stonehenge's builders.
It is the first time human remains have been found that link the mysterious ceremonial site with the north Pembrokeshire origins of the 80 standing stones.
Dr Andrew Fitzpatrick, from Wessex Archaeology, who excavated the site, said, "In medieval times, people believed that the stones could only have been brought to Stonehenge by Merlin the Wizard.
"For the first time we have found the mortal remains of one of the families who were almost certainly involved in this monumental task."
Archaeologists have named the Welshmen the Boscombe Bowmen because they were found buried with arrowheads.
The remains were dug up near the site where the Amesbury Archer was found two years ago. Although he lived at the same time, he came from central Europe.
Pottery fragments buried with him match those found with the Welsh family.
The Boscombe Bowmen grave is unusual because it contains the remains of an entire family, including three children, a teenager and three men. The shape of their skulls shows at least three of the party were related.
They were found in May 2003 when QinetiQ, a technology company operating on Boscombe Down airfield, dug a trench to lay water pipes and electrical cable.
QinetiQ archaeologist Colin Kirby, who stumbled across the 2,300BC grave, said, "On the second day of the excavations, I noticed human remains in the side of a water pipe trench.
"On investigating the spoil from the trench, fragments of beaker pottery and an arrowhead emerged.
"This was very exciting as it showed that the burial was probably Bronze Age and may be linked to the Amesbury Archer.
"I immediately informed Wessex Archaeology."
The Archer's burial is the wealthiest in Europe found from this period. Grave goods show he was clearly wealthy and may have been held in high esteem for importing metal working skills from Europe.
Metal may hold the key to why an ancient society chose Preseli bluestones for a monument more than 200 miles away.
Dr Fitzpatrick said beaker pottery of the type found with the Bowmen and the archer has also been found in county Kerry, Ireland.
The Preseli mountains could have been an important landmark for prospectors travelling around western Britain looking for sources of copper at the dawn of the Bronze Age, he said.
"Why people know of either Stonehenge or why people know of Preseli is the thing that people are beginning to tie together with people travelling and looking for metal," Dr Fitzpatrick said.
The stone circles at Stonehenge were built from two types of rock. The massive goal-like structures are sarsen sandstone from Marlborough, 20 miles north of Stonehenge.
But this find brings experts no closer to understanding how the bluestone, which was used to create the inner circle of smaller standing stones, was hauled to Salisbury Plain.
Dr Fitzpatrick said, "It is an astonishing thing to have done and people must have regarded Preseli as a truly magical place because they made the enormous effort to transport stone all the way over 200 miles, so there must have been something in the stone or the spirit of the place."
Scientists can locate where the Bowmen came from bythe enamel on their teeth. Asit forms it retains a fingerprint of the local environment by locking in oxygen and strontium isotopes. Tests by the British Geological Survey showed the men came from an area with high radiation background, like WestWales.