Peregrin Took
Denethor prepared to burn himself and his son upon a funeral pyre, believing Faramir to be beyond cure. Only the intervention of the hobbit Peregrin Took, Beregond (a Guard of the Citadel) and Gandalf saved Faramir, but Denethor immolated himself before they could stop him. Tolkien indirectly states that Théoden's death could have been prevented if Gandalf had helped the Rohirrim instead, as he had intended.