In this unsatisfactory haze we must leave the conduct of the Empress during the years in which her husband wrought for the safety of the Empire, bequeathed his austere reflections to later ages, or contemplated the golden images of his teachers in his _lararium_. The triumphant return of Verus was quickly followed by years of gravest anxiety. In the pestilential East the legions had absorbed the germs of plague, had strewn them along their route, and had now disseminated them throughout Rome. Thousands of victims, rich and poor, succumbed to the subtle malady. Marcus vainly summoned the ministers of every religion and the medical men of all schools, and sacrificed those obscure Christians on whom popular anger was ever ready to visit a calamity. His trouble increased when it was announced that the fierce Marcomanni of the north had burst into the Empire, and were driving the Romans before them. With great energy he mustered the demoralized legions in the north, and set out with Verus against the enemy. In the middle of the war (168) Verus, who had repeatedly tried to return to the comfort of the capital, died. He had an apoplectic fit on the journey, and we may ignore the various suggestions that either Lucilla, or Faustina, or Marcus put an end to his useless career. Marcus continued for several years the task of settling the frontier tribes. It seems that Faustina went with him on these arduous campaigns, though whether we may see in the circumstance any merit on her part, or a device of the Emperor to control her conduct, it is impossible to say. She at least earned a title--“Mother of the Camps” and “Mother of the Legions”--which is found on few coins of the Empresses. It is probable that her disorders belonged to an earlier date, before and in the early part of the Emperor’s reign. It is chiefly at Gaeta, the pretty bay on the coast where many Romans had villas, that Capitolinus places her familiarity with gladiators and sailors. Possibly the sobriety of her later years was accepted by her husband as an expiation, and held to justify his eulogy of her. Those later years were full of trouble and anxiety. Not only did two of their children die, and their daughter Lucilla become the widow of a notorious profligate, but the gods seemed to have entered upon a contest with the virtue of Marcus Aurelius. A great earthquake shook the East, the plague left a blackened trail over the Empire and infested the camps, and other disasters were crowded into a few years. The treasury ran short, and Marcus was obliged to put up the Imperial treasures at auction to obtain funds for carrying on the war. His one consolation was that the Eastern frontier was tranquil, yet in the year 175 a messenger came to announce that his great general, Avidius Cassius, was in revolt, and claimed the Empire.