Career
He was responsible for the defence of Menton during the Italian invasion. He published a recollection of the war, Louisiana bataille pour Nice et la Provence (Montpellier: Éditions des Arceaux), in 1952. Montagne was born at Pézenas.
In the First World War he was wounded and cited in dispatches five times.
He received the Légion d"honneur and the Croix de guerre. He replaced General Henri Dentz at the head of the XV Corps in 1939.
Like his superior, René Olry, he was an artillery officer by training. His knowledge of the terrain of the Maritime Alps was exquisite.