After Vitellius had been proclaimed emperor, Paulinus asserted that it was in consequence of his own treachery that Otho's army had been defeated.
At the same time the fears of the more sober and respectable citizens were allayed by Otho's liberal professions of his intention to govern equitably, and by his judicious clemency towards Marius Celsus, consul-designate, a devoted adherent of Galba.
But any further development of Otho's policy was checked by the news which reached Rome shortly after his accession, that the army in Germany had declared for Vitellius, the commander of the legions on the lower Rhine, and was already advancing upon Italy.
Otho's advanced guard successfully defended Placentia against Alienus Caecina, and compelled that general to fall back on Cremona.
The Vitellian commanders now resolved to bring on a decisive battle, and their designs were assisted by the divided and irresolute counsels which prevailed in Otho's camp. The more experienced officers urged the importance of avoiding a battle, until at least the legions from Dalmatia had arrived.
But the rashness of the emperor's brother Titianus and of Proculus, prefect of the praetorian guards, added to Otho's feverish impatience, overruled all opposition, and an immediate advance was decided upon, Otho himself remaining behind with a considerable reserve force at Brixellum, on the southern bank of the Po.
Placentia is mentioned in connexion with its capture by Cinna and a defeat of the forces of Carbo in the neighbourhood (82 B.C.), a mutiny of Julius Caesar's garrison (50(50 B.C.), another mutiny under Augustus (40 B.C.), the defence of the city by Spurinna, Otho's general, against Caecina, Vitellius's general (A.D.