7th August 1927. 4 porters from Courmayeur conclude the first climb of Pere Eternel, a granite obelisk, 3224 m high, between the Entreves and Brenva glaciers, in the Mont Blanc massif. A feat that even the greatest Courmayeur guides thought was impossible. Instead the young porters, Arthur and Oswald Ottoz, Albin Pennard and Laurent Grivel, discovered a trick to conquer the key passage of the climb. Without realizing it they began a new climbing technique: the artificial one. The historical reconstruction of the climb was made by four Courmayeur guides on the basis of information given them by Edouard Pennard, Albin's son, and francois Thomasset, who was the first to repeat the climb in 1932.