The room takes its name from frescoes depicting the life of Emperor Constantine the Great. The episodes are all described by the tabula below, and find their place among allegorical figures and symbolic landscapes. The ceiling of this hall, on the other hand, was reconstructed in the 19th century according to the design of architect Poletti. The room highlights the importance of Emperor Constantine from whose conversion we owe the end of the persecutions and the possibility of worship for Christians sanctioned by the Edict of Milan (313 A.D.).