Zosimus, New History 2.42

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 ZosimusNew 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.

[2.42.1] Constans, having thus removed his brother, exercised every species of cruelty toward his subjects, exceeding the most intolerable tyranny. He purchased some well favored barbarians, and had others with him as hostages, to whom he gave liberty to harrass his subjects as they pleased, in order to gratify his vicious disposition. In this manner he reduced all the nations that were subject to him to extreme misery. 

[2.42.2] This gave uneasiness to the court guards who, perceiving that he was much addicted to hunting, placed themselves under the conduct of Marcellinus, prefect of the treasury, and Magnentius who commanded the Joviani and Herculiani (two units so termed), and formed a plot against him in the following manner.

[2.42.3] Marcellinus reported that he meant to keep the birthday of his sons, and invited many of the superior officers to a feast. Amongst the rest Magnentius rose from table and left the room; he presently returned, and as it were in a drama stood before thorn clothed in an imperial robe. 

[2.42.4] Upon this all the guests saluted him with the title of king, and the inhabitants of Augustodunum, where it was done, concurred in the same sentiment. This transaction being rumored abroad, the country people flocked into the city, while at the same time a party of Illyrian cavalry who came to supply the Celtic legions, joined themselves with those that were concerned in the enterprize. 

[2.42.5] When the officers of the army were met together, and heard the leaders of the conspiracy proclaim their new emperor, they scarcely knew the meaning of it; they all, however, joined in the acclamation, and saluted Magnentius with the appellation of Augustus. When this became known to Constans, he endeavored to escape to a small town called Helena, which lies near the Pyrenean mountains. He was taken by Gaison, who was sent with some other select persons for that purpose, and being destitute of all aid, was killed.