Zosimus, New History 2.53
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.
[2.53.1] Constantius now gaining the victory, by the army of Magnentius taking to flight, a terrible slaughter ensued. Magnentius, deprived of all hope and apprehensive lest the remnant of his army should deliver him to Constantius, deemed it best to retire from Pannonia and to enter Italy, in order to raise an army there for another attempt.
[2.53.2] But when he heard that the people of Rome were in favor of Constantius, either from hatred to himself, or because they had heard of the event of the battle, he resolved to cross the Alps, and .seek for himself a refuge among the nations on that side.
[2.53.3] Hearing however that Constantius had likewise engaged the barbarians near the Rhine against him, and that he could not enter Gaul, as some officers had obstructed his passage thither in order to make their court to Constantius, nor through Spain into Mauritania, on account of the Roman allies there who studied to please Constantius. In these circumstances he preferred a voluntary death to a dishonorable life, and chose rather to die by his own hand than by that of his enemy.