The late period of the Glyptotek’s Roman Portrait Collection includes the Severan Dynasty, the so-called soldier-emperors and individual emperors up to the time of Constantine the Great: that is to say the 2nd, 3rd and the beginning of the 4th century. These were very troubled times for Rome and one emperor succeeded another at intervals of only a few years. Constantine the Great adopted the Christian faith after becoming sole ruler of the Roman Empire following the Battle of the Milvian Bridge in 312: this marks the end of the Roman Imperial era proper and the beginning of the Christian Byzantine age.