Stonehenge: DNA reveals origin of builders BBC - April 16, 2019
The ancestors of the people who built Stonehenge travelled west across the Mediterranean before reaching Britain, a study has shown. Researchers compared DNA extracted from Neolithic human remains found across Britain with that of people alive at the same time in Europe. The Neolithic inhabitants appear to have travelled from Anatolia (modern Turkey) to Iberia before winding their way north. They reached Britain in about 4,000BC.
Stonehenge itself evolved in several construction phases spanning at least some 1500 years. However there is evidence of large scale construction both before and afterwards on and around the monument that perhaps extends the landscape's time frame to 6500 years.
Dating and understanding the various phases of activity at Stonehenge is not a simple task; it is complicated by poorly kept early excavation records, surprisingly few accurate scientific dates and the disturbance of the natural chalk by periglacial effects and animal burrowing. The modern phasing most generally agreed by archaeologists is detailed below. Features mentioned in the text are numbered and shown on the plan, right, which illustrates the site as of 2004. The plan omits the trilithon lintels for clarity. Holes that no longer, or never, contained stones are shown as open circles and stones visible today are shown colored. It is widely assumed that Stonehenge once stood as a magnificent "complete" monument; we should be aware that this cannot be proved, since around half of the stones that should be present are in fact missing, and since many of the assumed stone sockets have never actually been recorded through excavation.