81—Titus died, to the great grief and loss of mankind, and was succeeded by his brother, Domitian, who was one of the most infamous rulers that ever desolated the earth. He raised a violent persecution against the Christians for refusing to adore his statues and worship him as a god. Among the victims was his own cousin, Clemens, who had embraced Christianity. He 96—was assassinated by his wife and officers in self-defense, and the senate proclaimed Nerva, a native of Crete, emperor. He was remarkable for his lenity and all the gentle virtues. He was followed, after a reign of two 98—years, by Trajan, whom he had adopted as his colleague and successor, who is said to have been the greatest and most deserving person of his time. He was, by birth, a Spaniard, was wise and successful as a warrior and statesman, and extremely noble as a man. He bridged the Danube and the Euphrates rivers and conquered both the Germans and Parthians on the north and east of the empire. A stain on his memory was the persecution of the Christians. 117—He was succeeded by Adrian, in whose reign all the Roman laws, or annual edicts of the prætors, were compiled into one body, and law assumed the dignity of a science. He promoted literature, but continued the persecution of the Christians. A rebellion of the 139—Jews was punished with merciless severity. He was followed by Antoninus Pius, who suspended all persecution of Christians, promoted the best interests of all parts of the empire, and introduced, during a prosperous reign of twenty-two years, the most important reforms into every part of the government. 161—Marcus Aurelius, called the Philosopher, succeeded. He carried on a successful war with the Germans, and made the welfare of his subjects his special care, but was seduced, by the pagan philosophers, into a persecution of the Christians. Having discovered his error he stopped it, toward the close of his reign. Commodus, 180—his son, inherited the purple. He also inherited a vicious and cruel disposition, and received a demoralizing education from his mother. He was a monster of vice and cruelty. He was assassinated in 192—his bed by his own family and guards to save their lives. Pertinax reigned three months, but, attempting to restrain the license of the soldiery, he was murdered by them. The soldiers in Rome then proclaimed that the empire was for sale, and a rich merchant, Didius, bought it from them and reigned in Rome two months, 193—when he was also slain by the army. Septimus Severus, an able general, seized the purple which he secured against many rivals, and retained for eighteen years. His vigor alone prevented general anarchy, but he was systematically cruel.