After the death of Severus the Thracian served with equal fidelity under his son Caracalla, whose favor and esteem he won. During the short reign of the profligate and effeminate Elagabalus, Maximin withdrew from the court, but he returned when Alexander Severus, one of the noblest of Roman emperors, came to the throne. The new monarch was familiar with his ability and the incidents of his unusual career, and raised him to the responsible post of tribune of the fourth legion, which, under his rigid care, soon became the best disciplined in the whole army. He was the favorite of the soldiers under his command, who bestowed on their gigantic leader the names of Ajax and Hercules, and rejoiced as he steadily rose in rank under the discriminating judgment of the emperor. Step by step he was advanced until he reached the highest rank in the army, and, but for the evident marks of his savage origin, the emperor might have given his own sister in marriage to the son of his favorite general. The incautious emperor was nursing a serpent. The favors poured upon the Thracian peasant failed to secure his fidelity, and only nourished his ambition. He began to aspire to the highest place in the empire, which had been won by many soldiers before him. Licentiousness and profligacy had sapped the strength of the army during the weak preceding reigns, and Alexander sought earnestly to overcome this corruption and restore the rigid ancient discipline. It was too great a task for one of his lenient disposition. The soldiers were furious at his restrictions, many mutinies broke out, his officers were murdered, his authority was widely insulted, he could scarcely repress the disorders that broke out in his immediate presence. This sentiment in the army offered the opportunity desired by Maximin. He sent his emissaries among the soldiers to enhance their discontent. For thirteen years, said these men, Rome had been governed by a weak Syrian, the slave of his mother and the senate. It was time the empire had a man at its head, a real soldier, who could add to its glory and win new treasures for his followers. Alexander had been engaged in a war with Persia. He had no sooner returned than an outbreak in Germany forced him to hasten to the Rhine. Here a large army was assembled, made up in part of new levies, whose training in the art of war was given to the care of Maximin. The discipline exacted by Alexander was no more acceptable to the soldiers here than elsewhere, and the secret agents of the ambitious Thracian found fertile ground for their insinuations.