Zosimus, New History 2.41
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.
[2.41] In the mean time Constantine and Constans were disputing for that part of Africa which belonged to Carthage, and for Italy. Constans, who wished to surprise his brother, concealed his enmity for three years. He took occasion, when he was in a province that was attached to himself, to send soldiers to him, on pretence of assisting him in the war against the Persians, but in reality to assassinate him by surprise. This they accordingly performed. Such was the end of Constantine.