WITH the assassination of Domitian the principle of heredity disappeared for a century from Roman monarchy. The Senate had never recognized inheritance as a source of sovereignty; now, after 123 years of submission, it reasserted its authority; and as in Rome’s beginnings it had chosen the king, now it named one of its own members princeps and imperator. It was an act of courage intelligible only when we remember that the vigor of the Flavian family was exhausted in that same generation which had seen the vitality of the Senate renewed by Italian and provincial blood.
Marcus Cocceius Nerva was sixty-six when supremacy surprised him. The colossal Nerva of the Vatican shows a handsome and virile face; no one would suppose that this was a respectable jurist with a bad stomach, a mild and amiable poet who had once been hailed as “the Tibullus of our time.”1 Perhaps the Senate had chosen him for his gray harmlessness. He consulted it on all policies, and kept his pledge never to be the cause of death to any of its members. He recalled Domitian’s exiles, restored their property, and moderated their revenge. He distributed 60,000,000 sesterces’ worth of lands among the poor, and established the alimenta—a state fund to encourage and finance parentage among the peasantry. He annulled many taxes, lowered the inheritance dues, and freed the Jews from the tribute that Vespasian had laid upon them. At the same time he repaired the finances of the state by economy in his household and his government. With reason he thought that he had been just to all classes, and remarked that “I have done nothing that could prevent me from laying down the imperial office and returning to private life in safety.”2 But a year after his accession the Praetorian Guard, which had been forestalled in his nomination and resented his economy, besieged his palace, demanded the surrender of Domitian’s assassins, and killed several of Nerva’s councilors. He offered his throat to the swords of the soldiers, but they spared him. Humiliated, he wished to abdicate, but his friends persuaded him, instead, to return to Augustus’ example and adopt as his son and successor a man acceptable to the Senate and capable of ruling not only the Empire, but the Guard as well. The greatest debt that Rome owed Nerva was that he chose Marcus Ulpius Traianus to succeed him. Three months later, after a reign of sixteen months, he passed away (98).
The principle of adoption thus accidentally restored meant that each emperor, as he felt his powers decline, would associate with himself in rule the ablest and fittest man he could find, so that when death came there would be neither the absurdity of a Praetorian elevation, nor the risk of a natural but worthless heir, nor a civil war among competitors for the throne. It was a lucky chance that no son was born to Trajan, Hadrian, or Antoninus Pius, and that each could apply the adoptive plan without slighting his offspring or his own parental love. While the principle was maintained it gave Rome “the finest succession of good and great sovereigns the world has ever had.”3