Otho, who had gone to Rome with Galba, seized the opportunity of Galba’s mistake to place himself on the throne. He had long solicited the favour of the soldiers and people, had given away entire estates to individuals, had, when Galba dined with him, given money to the emperor’s escort, and Galba had overlooked all this, because one of his favourites, Vinius, whose daughter Otho wished to marry, had come to a secret understanding with the latter. Otho instituted a formal conspiracy, corrupted the soldiers by gifts and promises, and had himself proclaimed emperor in a camp of the prætorians, a few days after Piso’s appointment. He left the camp at the head of the soldiers who had chosen him, entered the town, killed Galba and his co-regent, and was acknowledged emperor by the people and senate. This took place on the 15th of January of the year 69, when Galba had only reigned seven months and a few days.
The new emperor only maintained his rule for three months. All the provinces and armies swore allegiance to him after Galba’s death, only the legions of the Rhine and Upper Germany denied him obedience. They had already rebelled against Galba, and proclaimed the leader of the troops on the lower Rhine, Aulus Vitellius, emperor, as they had not been recompensed by Galba for the support they had given him against Nero. This rival, although other legions declared for him, would not in himself have been dangerous to Otho, as he had become so enervated by self-indulgence that he was wanting in activity and energy as well as in decision; but in Fabius Valens and Aulus Cæcina, he possessed two able generals, who placed themselves at the head of the legions in his stead.
With the rebellious troops they crossed the Alps into upper Italy and fell upon Otho, who had hastily collected as many soldiers as possible and led them against the enemy. At first the generals of Vitellius were the losers in a few small engagements, as mutual jealousy induced them to act separately, but as soon as they concentrated themselves they were far superior to their adversaries. Otho ought, therefore, to have done everything to delay the crisis until the reinforcements which he was expecting from the provinces of the Danube had arrived. He nevertheless did the reverse, and throughout the entire war showed himself a worthy comrade of Nero.
He had been the husband of the notorious Poppæa Sabina; had formerly participated with his imperial friend in all kinds of pleasures, and had indulged in so much dissipation that he had not only fallen deeply into debt, but had also become enervated and incapable of any exertion. This had already become apparent in the rebellion against Galba; for he had lost all courage at the moment of action, and would have given the whole thing up had not his fellow-conspirators compelled him to persist in his designs. Besides he was no general. His troops, which for the greater part consisted of prætorians and soldiers of Nero, clung to him with devotion, and were eager to fight, but they did not trust their officers and would no longer take orders from them. This determined him to bring the fight to a speedy end, as he felt that at any moment he might be deserted by his own people. In spite of this, as he had not been present in the earlier smaller fights, so now he took no personal share in the great battle which was to decide his own fate.
In the vicinity of Cremona, Cæcina and Valens fell on Otho’s army. It was beaten, suffered considerable loss, and then the greater part went over to the enemy. Otho’s cause was, nevertheless, by no means lost; for the prætorians adhered steadfastly to him, the legions of the provinces of the Danube were already on the march, and the entire East as well as Africa was open to him. Only he was too indolent and effeminate to be able to face continuous exertions and hardships, and from the example of his beaten army he saw how ephemeral the devotion of his soldiers had been. So he lost courage, and decided, in spite of the remonstrances and requests of his friends, to put an end to his life. He stabbed himself to the heart with a firmness rarely found in a voluptuary, and by this action won for himself the reputation with posterity of having purchased the peace of his country with his own life.