The Mithraeum, which was built at the end of the 2nd century A.D., is an underground cavern dedicated to the cult of the Persian god Mithra, and is of great interest for the study of the dissemination of eastern religions in the Campania region. The main room, which is entered through a cryptoporticus, has a barrel-vault ceiling painted with red and blue stars. On the back wall, above the altar, is a fresco depicting Mithra as a young man clothed in a colourful oriental costume killing the bull. The scene takes place in front of the entrance to a cave, in the presence of several figures. Either side are two dadophoroi clothed in Phrygian garb and armed with bow and arrows. At the bottom are the heads of Oceanus and Terra; at the top the Sun and the Moon. The podium facades are decorated with scenes showing the initiation of a follower, who, nude and accompanied by priests, passes through the various stages of purification. Worship of Mithra spread following the development of new cults, in Capua as well as other places, brought about as a result of commercial trade with the East. Mithra was the Persian god of light and embodied all the virtues that it was thought a Roman soldier should possess. Those who worshipped him were sworn to secrecy, which is why little or nothing is known of the rites, apart from the information provided by paintings and inscriptions found in various sanctuaries. Legend has it that the Sun ordered Mithra to kill a great bull: the beast was hunted, captured and sacrificed in a cave. According to myth, Mithra created the world following this feat: when the blood of the dying bull spurted out onto the earth, life sprang forth from it. In fact many paintings depict grain sprouting from the bull’s tail to symbolise Mithra having brought life to earth. It was thought that Mithra would guarantee salvation and eternal life, but initiation was not open to everyone. Women were excluded from it, while men had to prove their loyalty by undergoing ordeals. Initiations took place in cave-like sanctuaries to recall, through the ritual of baptism, the place where the bull was slain. In 394 A.D. Theodosius banned the cult, considering it to be a devilish practice; as a result Mithraism disappeared altogether.