Firstly I must apologise I have only just discovered and come across your response Graham. and recently delved back into the family tree William Martin is my husbands x2 great grandfather. He is descended from his 5th son Edwin Martin. I had managed to go back 2 generations but are not positive. I would love to hear what other info you may have I beleive they were stonemasons but Edwin moved to Westonzoyland Somerset as a provident insurance sales man.