It has been suggested that the Finnish word ''Suomi'' is first attested the Royal Frankish Annals annal for 811, which mentions a person called ''Suomi'' among the Danish delegation at a peace treaty with the Franks. If so, it is also the earliest evidence for the change from the proto-Finnic monophthong  to the Finnish diphthong . However, some historical linguists view this interpretation of the name as unlikely, supposing another etymology or that the spelling originated as a scribal error (in which case the sound-change  >  could have happened much later).