The War between Otho and Vitellius
(March and April)
Once Caecina emerged from the Alps toward the end of March, he swiftly overran much of the western half of the Transpadana, that part of Italy north of the River Po. He already had four good bases in the region, Eporedia, Vercellae, Novaria, and Mediolanum. Tacitus adds that the local inhabitants felt no loyalty to Otho or Vitellius and did not care who won the war, because a century of peace had schooled them to bow to superior force, no matter who applied it. The comment loses much of its sting as soon as we ask what else they could have done. Besides, Caecina took care not to alienate them. He kept his column on a tight rein as he moved south. And surprise appears to have been the tactic used by his advance forces, the auxiliaries sent on ahead, as they neutralized Othonian units in the area. Tacitus reports that a cohort of Pannonians was taken prisoner near Cremona, while 100 cavalry and 1,000 marines (drawn perhaps from the Ravenna fleet, perhaps from the squadron stationed earlier at Forum Julii) were captured as they made their way from Placentia on the southern bank to Ticinum (Pavia) on the northern. Tacitus does not say that Caecina's advance guard occupied Cremona when they rounded up the Pannonians there. But if they did not, their activity was probably enough to persuade the inhabitants to open the gates as soon as Caecina himself appeared. Either way, Tacitus seems to have taken it for granted that his readers would know that Cremona and Placentia were the keys to north Italy. They had been founded in 219 B.C., the former on the northern bank of the Po and the latter on the southern, as bulwarks against invasions out of the Alps, and the Romans still viewed them as such in 69.
Tacitus' refusal to labor the obvious enables him to dwell on what was for him a more congenial and significant topic, the petty-mindedness with which the leading townsfolk throughout the area insisted on being treated with a deference they had not earned. As Caecina marched south, Tacitus says, the magistrates of the various towns came out to meet him in full official dress. They were put out by what they regarded as the arrogance of a man who received them wearing a parti-colored cloak