is it a film?
No, a novel.
Bertrand du Guesclin
Bertrand du Guesclin appears as a character in Arthur Conan Doyle's 1891 historical novel "The White Company"
when did the battle of pontvallain take place? 4 December 1370 who battled against whom? French army and  English force. who led the former? Bertrand du Guesclin who won the battle? The French army. has the leader of the army been honored with any rank? Yes, he was a Breton knight. when was he appointed as one? 1354 were there any references of him in books or in movies? Yes, in "The White Company".
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Bertrand du Guesclin [SEP] Cultural references
Bertrand du Guesclin appears as a character in Arthur Conan Doyle's 1891 historical novel "The White Company", set in 1366. The protagonists first encounter him in Chapter 24, "How a Champion Came Forth From the East to the Lists", and again in Chapter 28, "How the Comrades Came over the Marches of France".