Hence it was, and from this original precedent of Augustus, aided by the constitution which he had given to the office of imperator, that up to the era of Dioclesian, no prince had dared utterly to neglect the senate, or the people of Rome. He might hate the senate, like Severus, or Aurelian; he might even meditate their extermination, like the brutal Maximin. But this arose from any cause rather than from contempt. He hated them precisely because he feared them, or because he paid them an involuntary tribute of superstitious reverence, or because the malice of a tyrant interpreted into a sort of treason the rival influence of the senate over the minds of men. But, before Dioclesian, the undervaluing of the senate, or the harshest treatment of that body, had arisen from views which were _personal_ to the individual Cæsar. It was now made to arise from the very constitution of the office, and the mode of the appointment. To defend the empire, it was the opinion of Dioclesian that a single emperor was not sufficient. And it struck him, at the same time, that by the very institution of a plurality of emperors, which was now destined to secure the integrity of the empire, ample provision might be made for the personal security of each emperor. He carried his plan into immediate execution, by appointing an associate to his own rank of Augustus in the person of Maximian--an experienced general; whilst each of them in effect multiplied his own office still farther by severally appointing a Cæsar, or hereditary prince. And thus the very same partition of the public authority, by means of a duality of emperors, to which the senate had often resorted of late, as the best means of restoring their own republican aristocracy, was now adopted by Dioclesian as the simplest engine for overthrowing finally the power of either senate or army to interfere with the elective privilege. This he endeavored to centre in the existing emperors; and, at the same moment, to discourage treason or usurpation generally, whether in the party choosing or the party chosen, by securing to each emperor, in the case of his own assassination, an avenger in the person of his surviving associate, as also in the persons of the two Cæsars, or adopted heirs and lieutenants. The associate emperor, Maximian, together with the two Cæsars--Galerius appointed by himself, and Constantius Chlorus by Maximian--were all bound to himself by ties of gratitude; all owing their stations ultimately to his own favor. And these ties he endeavored to strengthen by other ties of affinity; each of the Augusti having given his daughter in marriage to his own adopted Cæsar. And thus it seemed scarcely possible that a usurpation should be successful against so firm a league of friends and relations.