Pierre Lesueur, born in Clichy (France) on January 23, 1928, is one of the representatives of the famous group of Parisian climbers who marked the history of French mountaineering in the 1950s, with in particular the first of the face south of Aconcagua. During the week, while Robert Paragot repairs typewriters at Social Security, Pierre Lesueur cuts metal parts at the factory. On weekends, they meet up with the whole gang in Fontainebleau to climb the rocks or, better yet, hitchhike to Chamonix, with the heavy pitons made by Lesueur in their backpacks.