King Edward the III was the medieval ruler who launched an extended war against France that contributed to the development of distinct national identities in Europe.
Explanation:
King Edward the III of England believed that he was the 'rightful king' of the 'throne of France' and in order to conquer the same, he fought a number of battles with the then French rulers.
It was only after the treaty of Bretigny that Edward left his urge to conquer the throne of France.
