"Sir Agnate d'Arkeyl 1327ad"
cant find any record of this chap. WHere did you find this info?
its possible that arkell, may have been a comon norse word, there may be variants amoungst those descended from viking, angle, dutch familise.
I wonder if there is some university in denmark that has researched this word/families?
TEsting the dna of hereford arkells vs the dna of northumbria and yorkshire arkles might yield some common links??
DIdi the arkles in ireland, move there in 1100 to excape the normans, or where they there in the viking era?
Afraid, its seems that cracking this surname will be tricky!
I doubt we can get any interest from british universities, but dutch/daneish/german may be the ones to approach.