The Ecclesiastical History Of Sozomenus by Sozomen
Chapter XI.--The Tyrants who in the West at that Time rebelled against Honorius. They are wholly destroyed on account of the Emperor's Love of God.
During this period many tyrants rebelled against Honorius in the Western government. Some fell upon one another, while others were apprehended in a marvelous way, and so evidenced that the Divine love toward Honorius was not common. The soldiers in Britain were the first to rise up in sedition, and they proclaimed Mark as tyrant. Afterwards, however, they slew Mark, and proclaimed Gratian. Within four months subsequently they killed Gratian, and elected Constantine in his place, imagining that, on account of his name, he would be able to reduce the empire firmly under his authority; and for no other reason than this, several other persons of the same name were elected to the tyranny. Constantine passed over from Britain to Bononia, a maritime city of Gaul; and after inducing all the troops in Gaul and Aquitania to espouse his cause, he reduced to obedience the inhabitants of the regions extending to the mountains which divide Italy from Gaul, and which the Romans have named the Cottian Alps. He then sent his oldest son, Constans, whom he had already nominated Cæsar, and whom he afterwards proclaimed emperor, into Spain. Constans, after making himself master of this province, and appointing his own governors over it, commanded that Didymus and Verinian, relatives of Honorius, should be loaded with chains, and brought before him. Didymus and Verinian had at first differed among themselves, but a reconciliation was effected between them, when they found themselves menaced by the same danger. They combined their forces, which consisted chiefly of armed peasants and slaves. They attacked Lusitania in common, and slew many of the soldiers sent by the tyrant for their capture.