by a series of great princes, who derived their
obscure origin from the martial provinces of Illyricum. Within a period
of about thirty years, Claudius, Aurelian, Probus, Diocletian and his
colleagues, triumphed over the foreign and domestic enemies of the
state, reestablished, with the military discipline, the strength of the
frontiers, and deserved the glorious title of Restorers of the Roman
world.

The removal of an effeminate tyrant made way for a succession of heroes.
The indignation of the people imputed all their calamities to Gallienus,
and the far greater part were indeed, the consequence of his dissolute
manners and careless administration. He was even destitute of a sense of
honor, which so frequently supplies the absence of public virtue; and as
long as he was permitted to enjoy the possession of Italy, a victory of
the barbarians, the loss of a province, or the rebellion of a general,
seldom disturbed the tranquil course of his pleasures. At length, a
considerable army, stationed on the Upper Danube, invested with the
Imperial purple their leader Aureolus; who, disdaining a confined and
barren reign over the mountains of Rhaetia, passed the Alps, occupied
Milan, threatened Rome, and challenged Gallienus to dispute in the
field the sovereignty of Italy. The emperor, provoked by the insult, and
alarmed by the instant danger, suddenly exerted that latent vigor which
sometimes broke through the indolence of his temper. Forcing himself
from the luxury of the palace, he appeared in arms at the head of his
legions, and advanced beyond the Po to encounter his competitor. The
corrupted name of Pontirolo [1] still preserves the memory of a bridge
over the Adda, which, during the action, must have proved an object
of the utmost importance to both armies. The Rhaetian usurper, after
receiving a total defeat and a dangerous wound, retired into Milan. The
siege of that great city was immediately formed; the walls were battered
with every engine in use among the ancients; and Aureolus, doubtful
of his internal strength, and hopeless of foreign succors already
anticipated the fatal consequences of unsuccessful rebellion.

[Footnote 1: Pons Aureoli, thirteen miles from Bergamo, and thirty-two
from Milan. See Cluver. Italia, Antiq. tom. i. p. 245. Near this place,
in the year 1703, the obstinate battle of Cassano was fought between the
French and Austrians. The excellent relation of the Chevalier de Folard,
who was presen