Zosimus, New History 4.17
Zosimus (Greek Ζώσιμος): Early Byzantine, pagan author of a history of the Roman Empire, published in the first quarter of the sixth century CE.
The translation of Zosimus' New History offered here was printed in 1814 by W. Green and T. Chaplin in London, and was probably prepared by J. Davis of the Military Chronicle and Military Classics Office. The translator is anonymous. The text was found at Tertullian.org. The notes were added by Jona Lendering.
[4.17.1] Valentinian, roused by the intelligence of these events, marched from Celtica into Illyricum, for the purpose of opposing the Quadi and the Sarmatians, and consigned the command of his forces to Merobaudes, who was a person of the greatest military experience.
[4.17.2] The winter continuing unusually late, the Quadi sent ambassadors to him with insolent and unbecoming messages. These so exasperated the emperor, that through the violence of his rage, the blood flowed from his head into his mouth, and suffocated him. He thus died after having resided in Illyricum nearly nine months, and after a reign of twelve years.