BATTLE OF TZIRALLUM

Edward Gibbon has this to say about the battle:
Before Constantine marched into Italy, he had secured the
friendship, or at least the neutrality, of Licinius, the Illyrian
emperor. He had promised his sister Constantia in marriage to
that prince; but the celebration of the nuptials was deferred
till after the conclusion of the war, and the interview of the
two emperors at Milan, which was appointed for that purpose,
appeared to cement the union of their families and interests. ^78
In the midst of the public festivity they were suddenly obliged
to take leave of each other. An inroad of the Franks summoned
Constantine to the Rhime, and the hostile approach of the
sovereign of Asia demanded the immediate presence of Licinius.
Maximin had been the secret ally of Maxentius, and without being
discouraged by his fate, he resolved to try the fortune of a
civil war. He moved out of Syria, towards the frontiers of
Bithynia, in the depth of winter. The season was severe and
tempestuous; great numbers of men as well as horses perished in
the snow; and as the roads were broken up by incessant rains, he
was obliged to leave behind him a considerable part of the heavy
baggage, which was unable to follow the rapidity of his forced
marches. By this extraordinary effort of diligence, he arrived
with a harassed but formidable army, on the banks of the Thracian
Bosphorus before the lieutenants of Licinius were apprised of his
hostile intentions. Byzantium surrendered to the power of
Maximin, after a siege of eleven days. He was detained some days
under the walls of Heraclea; and he had no sooner taken
possession of that city, than he was alarmed by the intelligence,
that Licinius had pitched his camp at the distance of only
eighteen miles. After a fruitless negotiation, in which the two
princes attempted to seduce the fidelity of each other's
adherents, they had recourse to arms. The emperor of the East
commanded a disciplined and veteran army of above seventy
thousand men; and Licinius, who had collected about thirty
thousand Illyrians, was at first oppressed by the superiority of
numbers. His military skill, and the firmness of his troops,
restored the day, and obtained a decisive victory. The
incredible speed which Maximin exerted in his flight is much more
celebrated than his prowess in the battle. Twenty- four hours
afterwards he was seen, pale, trembling, and without his Imperial
ornaments, at Nicomedia, one hundred and sixty miles from the
place of his defeat. The wealth of Asia was yet unexhausted; and
though the flower of his veterans had fallen in the late action,
he had still power, if he could obtain time, to draw very
numerous levies from Syria and Egypt. But he survived his
misfortune only three or four months. His death, which happened
at Tarsus, was variously ascribed to despair, to poison, and to
the divine justice. As Maximin was alike destitute of abilities
and of virtue, he was lamented neither by the people nor by the
soldiers. The provinces of the East, delivered from the terrors
of civil war, cheerfully acknowledged the authority of Licinius.
The 'Battle of Tzirallum' was fought in 313 between the armies of Licinius and Maximinus. Licinius was the victor and Maximinus was forced to flee.