A military officer, geologist and archaeologist, in 1862, Alphonse Le Touzé de Longuemar became a correspondent of the CTHS. He joined the Commission de Topographie des Gaules in the same decade.

A passionate geologist and archaeologist in Poitou

A founding member of the Société des antiquaires de l'Ouest in 1834, and later its president, from 1843, Longuemar was also a member of the Société géologique. His many publications between 1851 and 1881 are testament not only to his attachment to the region of Vienne, but also to the strong links between geological studies and the birth of prehistory led by local scholars.

A noteworthy example of the documents produced by Alphonse de Longuemar is the album, conserved at the musée d'Archéologie nationale, which he gave to the museum in 1865 as testament to his personal contribution to the CTG’s work.