The Ecclesiastical History of Socrates Scholasticus

Thus did the emperor repress at that time the impetuosity of those who were disposed to cavil: and immediately departing from Antioch, he went to Tarsus in Cilicia, where he duly performed the funeral obsequies of Julian, after which he was declared consul. Proceeding thence directly to Constantinople, he arrived at a place named Dadastana, situated on the frontiers of Galatia and Bithynia. There Themistius the philosopher, with others of the senatorial order, met him, and pronounced the consular oration before him, which he afterwards recited before the people at Constantinople. And indeed the Roman empire, blest with so excellent a sovereign, would doubtless have flourished exceedingly, as it is likely that both the civil and ecclesiastical departments would have been happily administered, had not his sudden death bereft the state of so eminent a personage. For disease caused by some obstruction, having attacked him at the place above mentioned during the winter season, he died there on the 17th day of February, in his own and his son Varronian’s consulate, in the thirty-third year of his age, after having reigned seven months.

This book contains an account of the events which took place in the space of two years and five months.