The unanswered question is how these sacred trees often survived as hallowed sites between Celtic times and the Anglo-Saxon conversion. Of course, the sites being under venerable churches makes the answer more difficult but, since there was a reluctance in medieval times to bury to the north of the church, there may still be places where one can dig.
Sir: David Keys seems to report as a generality that after the Roman conquest sacred trees were removed ("Ancient Surrey temple shows Celts were tree-worshippers", 11 September). Not so. Large numbers of parish churches have been built to the south of yew trees that are now generally recognised to be some 3,000 years old.