He was chosen emperor in his forty-third year by the officers of the army at Nicaea in Bithynia in 364, and shortly afterwards named his brother Valens colleague with him in the empire.
Spain, the Gauls, Britain and Africa, leaving to Valens the eastern half of the Balkan Peninsula, Greece, Egypt, Syria and Asia Minor as far as Persia.
In Egypt, if not even before leaving Italy, he had become intimately acquainted with Melania, a wealthy and devout Roman widow; and when she removed to Palestine, taking with her a number of clergy and monks on whom the persecutions of the Arian Valens had borne heavily, Rufinus (about 378) followed her.
Far from being ambitious or scheming, he was lazy and selfindulgent, fond of eating and drinking, and owed his elevation to the throne to Caecina and Valens, commanders of two legions on the Rhine.
During his brief administration Vitellius showed indications of a desire to govern wisely, but he was completely under the control of Valens and Caecina, who for their own ends encouraged him in a course of vicious excesses which threw his better qualities into the background.