His claim to the throne was soon challenged by legions stationed in the Eastern provinces, who proclaimed their commander Vespasian emperor in his place. War ensued, leading to a crushing defeat for Vitellius at the Second Battle of Bedriacum. When he realised his support was wavering, Vitellius prepared to abdicate in favour of Vespasian, but was executed in Rome by Flavian forces on December 22 of 69.
In fact, he was never acknowledged as emperor by the entire Roman world, though at Rome the Senate accepted him and decreed to him the usual imperial honours. He advanced into Italy at the head of a licentious and rough soldiery, and Rome became the scene of riot and massacre, gladiatorial shows and extravagant feasting. To reward his victorious legionaries, Vitellius disbanded the existing Praetorian Guard and installed his own men instead.
Suetonius, whose father had fought for Otho at Bedriacum, gives an unfavourable account of Vitellius' brief administration: he describes him as unambitious and notes that Vitellius showed indications of a desire to govern wisely, but that Valens and Caecina encouraged him in a course of vicious excesses which threw his better qualities into the background. Vitellius is described as lazy and self-indulgent, fond of eating and drinking, and an obese glutton, eating banquets four times a day and feasting on rare foods he would send the Roman navy to procure. He is even reported to have starved his own mother to death- to fulfill a prophecy that he would rule long if his mother died first. Other writers, namely Tacitus and Cassius Dio, disagree with some of Suetonius assertions, even though their own accounts of Vitellus are scarcely positive ones.
Vitellius also banned astrologers from Rome and Italy from 1 October, 69. Some astrologers responded to his decree by anonymously publishing a decree of their own: "Decreed by all astrologers in blessing on our State Vitellius will be no more On the appointed date." In response, Vitellius executed any astrologers he came across.
In July 69, Vitellius learned that the armies of the eastern provinces had proclaimed a rival emperor; their commander, Titus Flavius Vespasianus. As soon as it was known that the armies of the East, Dalmatia, and Illyricum had declared for Vespasianus, Vitellius, deserted by many of his adherents, would have resigned the title of emperor.
It is said that he awaited Vespasian's army at Mevania. It was said that the terms of resignation had actually been agreed upon with Marcus Antonius Primus, the commander of the sixth legion serving in Pannonia and one of Vespasian’s chief supporters, but the praetorians refused to allow him to carry out the agreement, and forced him to return to the palace, when he was on his way to deposit the insignia of empire in the Temple of Concord. On the entrance of Vespasian's troops into Rome he was dragged out of some miserable hiding-place (according to Tacitus a door-keeper's lodge), driven to the fatal Gemonian stairs, and there struck down. His body was thrown into the Tiber according to Suetonius; Cassius Dio's account is that Vitellius was beheaded and his head paraded around Rome, and his wife attended to his burial. "Yet I was once your emperor," were the last and, as far as we know, the noblest words of Vitellius. His brother and son were also killed.