In her article called Where Witches Used to Meet, (I can’t find where this was published) Mollie Mordle-Barnes wrote:
The Rollright stones have been a favourite meeting place for witches for centuries. In Tudor times detailed reports of witches’ sabbaths were compiled by a witch hunting commission in Oxford. In the reign of Charles I one of these witches was hanged for attempting to murder her sister’s child by means of witchcraft. She was said to have attended numerous sabbaths at the stones and others held on Boar’s Hill, just outside Oxford.
The same article alludes to a notorious witches sabbath held at the stones on May 12th (Walpurgis night) 1949.