This book covers a century and a half of the history of the Roman Empire - from 117 to 284 AD. BC: the “golden age” of the empire, the reign of the Antonine dynasty (117–180 - Hadrian, Antoninus Pius, Marcus Aurelius); reign of the Severan dynasty: Septimius, Caracallo, Heliogabalus, Alexander (193–235); and the so-called “third-century crisis” (Maximinus to Numerianus, 235–284). The narrative stops at the threshold of a new era of temporary strengthening of the empire - when the emperors Diocletian (284–305) and Constant (306–337) managed to restore the relative unity of the state for another century. From several dedicatory addresses it follows that it was these emperors who entrusted write biographies of his predecessors to six historians: Aelius Spartianus, Julius Capitolinus, Vulcatius Gallicanus, Aelius Lampridius, Trebellius Pollio and Flavius Vopiscus. We know nothing about them, they wrote nothing more, and their names are not mentioned anywhere else. Their manner of presentation and style are the same - they all write like one person. Therefore, in modern science, these authors are usually called scriptores historiae Augustae, “authors of the history of the Augustans.”