[Sidenote: Success of Marius, who rolls back the tide of northern
emigration.]

It was in that period of civic strife, when factions and parties
struggled for ascendency--when the Gracchi were both reformers and
demagogues, patriots and disorganizes, heroes and martyrs--when
fortunate generals aimed at supreme power, and sought to overturn the
liberties of their country, that Rome was seriously threatened by the
barbarians. Both Celts and Teutones, from Gaul and Germany, formed a
general union for the invasion of Italy. They had successively defeated
five consular armies, in which one hundred and twenty thousand men were
slain. They rolled on like a devastating storm--some three hundred
thousand warriors from unconquered countries beyond the Alps. They were
met by Marius the hero of the African war, who had added Numidia, to the
empire--now old, fierce, and cruel, a plebeian who had arisen by force
of military genius--and the Gaulish hordes were annihilated on the Rhone
and the Po. The Romans at first viewed those half-naked warriors--so
full of strength and courage, so confident of victory, so reckless of
life, so impetuous and savage--with terror and awe. But their time had
not yet come. Numbers were of no avail against science, when science was
itself directed by genius and sustained by enthusiasm. The result of the
decisive battles of Aquae Sextiae and Vercellae was to roll back the tide
of northern immigration for three hundred years, and to prepare the way
for the conquests of Caesar in Gaul.

[Sidenote: The Social War.]

[Sidenote: Rise of Sulla.]

Then followed that great insurrection of the old states of Italy against