 One of Berhtwald 's letters has been preserved , sent to <unk> , Bishop of Sherborne , and asking <unk> to intercede with <unk> , the Abbot of Glastonbury , to ransom a slave . Another letter , this one addressed to Berhtwald , from <unk> , Bishop of London , also survives . The main interest in the second letter is that it is the oldest surviving letter close surviving in Western Europe . This second letter also relates that <unk> and Berhtwald had attended a <unk> which can be dated to sometime between 703 and 705 , where the kingdom of Wessex was threatened with excommunication . A charter witnessed by Berhtwald which mentions a supposed <unk> council , numbered 54 by Sawyer , is now known to be a fake , although the witness list may be based on a legitimate 8th century charter that no longer survives . Likewise , a charter with Berhtwald as a witness and relating to the 716 Council of <unk> is also known to be a 9th @-@ century forgery , although again it may have been based on actual documents from the council . 
