Would people such as William Wallace, Llewellyn the great and Owain Glyndwr have been seen as terrorists by the English? For instance, Glyndwr sacked and burned many marcher towns such as Welshpool. Would they be considered terrorists by the English? How would the Welsh have seen characters such as William Wallace, and the Scots have seen Owain or Llewellyn? I think this also interesting as many Welsh nobles fought against Scottish rebellions. How would continentals have viewed these characters too? Can a link be made between how modern terrorists in the middle east are viewed by Europeans? That's all for now, thanks in advance!
No, I don't think they would. First of all, terrorism and terrorist are a distinctly modern phenomenon (I'm thinking of modernity in its broadest sense here). When you say the English, you're really referring to the Kings and those members of the nobility loyal to the crown. To them, these people would have certainly been seen as rebels and an affront to the authority of the crown, but their tactics certainly weren't strange for any military leader of the day. If you look at the activities of the English armies in France during the fourteenth century, you find English royalty behaving in much the same way.