I have at last obtained a copy of the Trebullett Community Project book and a fascinating little tome it is too. It contains just the information I was looking for and confirms my hunch that some of the early Trecarrells were Templars. The Magdalene theme and motifs in Launceston Church were the clue. Peter Trecarrel (1140-1221) was Peter of Cornwall, emissary of King John. He wrote of his family going back to his greatgrandfather Theodulf from before 1066. It is not stated as to when the name was changed from de Esse to Trecarrel/ Trecarrell however. The writings of Peter of Cornwall, dated 1200, are in a work called 'De Omnibus' which is in the Lambeth Palace Library. The above information is from the Trebullett book as provided by Neil Burden. I have made notes should anyone be interested in further details. Thanks again Peter.