France–Italy border

Along the Alps

The high Alps between Mont Blanc and the Mediterranean have served as a natural frontier since the second century BC. Under the Treaty of Turin of 24 March 1860 Savoy and Nice passed to France, but the line drawn in 1861 departed from the watershed in places, leaving France without the heads of several valleys. Small changes followed at railway crossings, in the Mont Cenis tunnel in 1874 and on the Cuneo–Ventimiglia line in 1930.^[1]

After the Second World War France used the 1947 peace treaty with Italy to bring the border generally onto the watershed. Five areas totalling 693 km² went to France: the Little St Bernard Pass, the Mont Cenis plateau, Mont Thabor, the Chaberton, and the upper valleys of the Tinée, Vésubie and Roya with the towns of Tende and Brigue. A last shift of 200 metres in 1948 put a botanical institute and a Column of Jupiter at the Little St Bernard in France.^[1]

“take into account the configuration of the Mountains and the requirements of defence”^[1]

Mont Blanc

France and Italy have argued over Mont Blanc since the 18th century. Italy holds that the border splits the summits of Mont Blanc and the neighbouring Dôme du Goûter between the two countries; France holds that it passes around them, leaving both in France. About 75 hectares are in dispute, and melting glaciers are changing the shape of the mountain itself.^[2]