Perhaps it was without the consent of Constantina, that the new emperor formed a necessary, though dishonorable, alliance with the usurper of the West, whose purple was so recently stained with her brother's blood.
The intelligence of these important events, which so deeply affected the honor and safety of the Imperial house, recalled the arms of Constantius from the inglorious prosecution of the Persian war.

He recommended the care of the East to his lieutenants, and afterwards to his cousin Gallus, whom he raised from a prison to a throne; and marched towards Europe, with a mind agitated by the conflict of hope and fear, of grief and indignation.

On his arrival at Heraclea in Thrace, the emperor gave audience to the ambassadors of Magnentius and Vetranio.

The first author of the conspiracy Marcellinus, who in some measure had bestowed the purple on his new master, boldly accepted this dangerous commission; and his three colleagues were selected from the illustrious personages of the state and army.

These deputies were instructed to soothe the resentment, and to alarm the fears, of Constantius.