218. Macrinus is overthrown by Elagabalus, who succeeds him as emperor of Rome. This was accomplished by Mœsa, sister of Julia Domna, bribing a portion of the army to espouse the cause of her grandson Elagabalus.
219. Elagabalus arrives at Rome; he brings with him his Syrian idol, which he places in a stately temple.
220. The highest offices of the State are filled by Elagabalus with his vilest associates.
222. Alexander Severus (Alexianus) succeeds Elagabalus, who is slain by the prætorians; his mother, Soœmias, is killed with him.
223. All persecution of the Christians ceases in Rome.
Alexander Severus guided by his mother, Marnæa, who is created augusta.
224. The Persians, under Ardashir (known by the Greeks as Artaxerxes), revolt against the Parthians.
225. Marriage of Alexander Severus to Sulpitia Memmia.
226. Ardashir overthrows the Parthian kingdom; he founds the new Persian kingdom of the Sassanidæ.
228. Ulpian, prætorian prefect, endeavors to restrain the licentiousness of the guards; a mutiny ensues and he is put to death.