The Mound

Ancient secrets of Merlin’s Barrow unearthed

The Wiltshire landscape around Avebury and Silbury Hill is at the heart of prehistoric Britain, and has World Heritage designation. Now another monument can be added to its archaeological treasures: the Marlborough Mound.

The Mound lies in the heart of the grounds of Marlborough College, and has been interwoven with local folklore for hundreds of years. The town’s motto, Ubi nunc sapientis ossa Merlini (‘Where now are the bones of wise Merlin?’), echoes the myth which convinced generations that Merlin’s bones were buried under the Mound. These were the seductive Arthurian legends that may have drawn the interest of Tennyson and William Morris back to their connections with Marlborough and its Mound – or ‘Merlin’s Barrow’, as the burghers of the town claimed.

Not only has the Mound stimulated some of the region’s most enduring threads of mythology, it has also been recognised as a feature of considerable historical significance.  It was the motte on which the keep of Marlborough Castle was built fifty years after the Norman Conquest. Subsequently, it became the centrepiece of a major seventeenth century garden. The latest research, however, has extended its history back by three millennia.

Recent coring of the Mound at Marlborough College has produced four samples of charcoal, allowing radiocarbon dating for the first time. The samples, which came from different levels in the Mound, were taken from two bore holes through the height of the 19m monument, showing that it was built in the years around 2400 BC. This is the first positive evidence proving the theory that the castle motte is in fact a re-used prehistoric structure of the highest national standing.

Jim Leary, who led the recent archaeological investigations for English Heritage at the nearby Silbury Hill, and is co-author of the recently published ‘The Story of Silbury Hill’ coordinated EH’s contribution, which also included radiocarbon dating.  He says, “This is an astonishing discovery. The Marlborough Mound has been one of the biggest mysteries in the Wessex landscape. For centuries people have wondered whether it is Silbury’s little sister; and now we have an answer. This is a very exciting time for British prehistory.”

The Master of Marlborough College is equally enthusiastic: ‘We are thrilled at the discovery of another aspect of our rich history, and one which can be added to the educational opportunities at the school.’

The work is part of a major conservation programme being undertaken by the Marlborough Mound Trust, specially formed at the invitation of the College. The chairman of the Trust says that ‘the inspiration for this was our founder Eric Elstob, a former pupil at the College, whose generous legacy has provided the means for this work. He would have been totally delighted by this news.’

Note: As part of the College grounds, the Mound is strictly on private property.   For further details please contact: Donald Insall Associates, 7A Northumberland Buildings, Queen Square, BATH, BA1 2JB Telephone: 01225 469898 Email:


The Marlborough Mound Film - click here

Why was the Mound built and how did the local topography affect the choice of position? - click here

BBC Points West - The Marlborough Mound - click here

The Marlborough Mound Castle Reconstruction - click here