A geographer in the military, Antoine-Lucien Blondel was appointed a member of the Commission de Topographie des Gaules in 1858 .

A geographical engineer at the head of the Dépôt de la Guerre

A former student of the École Polytechnique, during the Restoration Blondel joined the École des ingénieurs géographes, which was then responsible for producing the grande carte d'état-major, a map for military use, at a scale of 1:80,000. Blondel worked on the Carte de France between 1824 and 1831 and rose though the military hierarchy. As a colonel, in 1851, he became chef de cabinet for the Minister of War, and in 1852, he was appointed head of the prestigious Dépôt de la Guerre, where he remained until 1867. Thanks to his support, the commission had access to the most accurate maps of its time.