XEE4170727 History of Gaul: Siege of Alesia by the Roman army (52 BC). A sentinel stands guard while the other soldiers dig a pit. Deep down, a catapult and an assault tower. Realization of a fortification around the city to prevent the Gauls from coming out and refuelling, and to protect themselves from attacks by the Gallic outside troops. in ???istoire de France learned by image and direct observation. Preparatory Course and First Year of Elements Course.??????GUESSING - TOURSEL. Illustrations by Ferdinand Raffin. 1923. DR by Raffin, Ferdinand (1870?-1948); Private Collection; (add.info.: History of Gaul: Siege of Alesia by the Roman army (52 BC), A sentinel stands guard while the other soldiers dig a pit. Deep down, a catapult and an assault tower. Realization of a fortification around the city to prevent the Gauls from coming out and refuelling, and to protect themselves from attacks by the Gallic outside troops. in ???istoire de France learned by image and direct observation. Preparatory Course and First Year of Elements Course.??????DEVINAT - TOURSEL, Illustrations by Ferdinand Raffin. 1923. DR); Stefano Bianchetti.