Bede’s Ecclesiastical History of England

In the year of our Lord 377, Gratian, the fortieth from Augustus, held the empire for six years after the death of Valens; though he had long before reigned with his uncle Valens, and his brother Valentinian. Finding the condition of the commonwealth much impaired, and almost gone to ruin, and impelled by the necessity of restoring it, he invested the Spaniard, Theodosius, with the purple at Sirmium.