disdain. One of the ambassadors of
the tyrant was dismissed with the haughty answer of Constantius; his
colleagues, as unworthy of the privileges of the law of nations, were
put in irons; and the contending powers prepared to wage an implacable
war. [75]

[Footnote 75: See Peter the Patrician, in the Excerpta Legationem p.
27.]

Such was the conduct, and such perhaps was the duty, of the brother
of Constans towards the perfidious usurper of Gaul. The situation and
character of Vetranio admitted of milder measures; and the policy of
the Eastern emperor was directed to disunite his antagonists, and to
separate the forces of Illyricum from the cause of rebellion. It was
an easy task to deceive the frankness and simplicity of Vetranio, who,
fluctuating some time between the opposite views of honor and interest,
displayed to the world the insincerity of his temper, and was insensibly
engaged in the snares of an artful negotiation. Constantius acknowledged
him as a legitimate and equal colleague in the empire, on condition that
he would renounce his disgraceful alliance with Magnentius, and appoint
a place of interview on the frontiers of their respective provinces;
where they might pledge their friendship by mutual vows of fidelity, and
regulate by common consent the future operations of the civil war. In
consequence of this agreement, Vetranio advanced to the city of Sardica,
[76] at the head of twenty thousand horse, and of a more numerous body
of infantry; a power so far superior to the forces of Constantius, that
the Illyrian emperor appeared to command the life and fortunes of his
rival, who, depending on the success of his private negotiations, had
seduced the troops, and undermined the throne, of Vetranio. The chiefs,
who had secretly embraced the party of Constantius, prepared in his
favor a public spectacle, calculated to discover and inflame the
passions of the multitude. [77] The united armies were commanded to
assemble in a large plain near the city. In the centre, according to the
rules of ancient discipline, a military tribunal, or rather scaffold,
was erected, from whence the emperors were accustomed, on solemn and
important occasions, to harangue the troops. The well-ordered ranks of
Romans and Barbarians, with drawn swords, or with erected spears, the
squadrons of cavalry, and the cohorts of infantry, distinguished by the
variety of their arms and ensigns, formed an immense circle round the
tribunal; and