Roman emperor A. D. 69, was descended from an ancient Etruscan family. His father L. Otho, who was consul in A. D. 33, had two sons, Marcus and L. Salvius Titianus. [See above, No. 2.] Marcus Otho was born in the early part of A. D. 32. He was of moderate stature, ill-made in the legs, and had an effeminate appearance. He was one of the companions of Nero in his debaucheries, till he was sent as governor to Lusitania, which he administered with credit during the last ten years of Nero's life [NERO, p. 1163a.]. Otho attached himself to Galba when he revolted against Nero, in the hope of being adopted by him and succeeding to the empire. But Galba, who knew Otho's character, and wished to have a worthy successor, adopted L. Piso, on the tenth of January, A. D. 69, and designated him as the future emperor. (Tac. Hist. 1.15.)

Otho thus saw his hopes disappointed. His private affairs also were in. a ruinous condition, and he resolved to seize the power which an astrologer had foretold him that he would one day possess. He enlisted in his design a few soldiers, and on the fifteenth of January he was proclaimed emperor by a mere handful of men, who, with their, swords drawn, carried him in a litter to the camp, where he was saluted emperor. Otho was ready to promise any thing and to stoop to any thing to extricate himself from his dangerous position, and to receive the prize at which he aimed (Tac. Hist. 1.36). A little vigour and decision on the part of Galba might have checked the rising. The matter was at last decided by Otho and the soldiers making their way into the forum, upon which the standardbearer of the cohort that accompanied Galba snatched from it the emperor's effigy, and threw it on the ground. This was the signal for deserting Galba, who received his death-blow from a common soldier.

The soldiers showed they were the masters of the emperor by choosing as praefecti praetorio, Plotius Firmus and Licinius Proculus; Flavius Sabinus, the brother of Vespasian, was made praefectus urbi. On the evening of the day in which Galba was murdered the senate took the oath of fidelity to Otho, who afterwards offered a sacrifice in the Capitol, with no favourable omens. The new emperor showed his moderation or his prudence by protecting against the fury of the soldiers, Marius Celsus, who had maintained his fidelity to Galba, and who showed the same devotion afterwards to the cause of Otho. The punishment of Tigellinus, the guilty encourager of Nero's crimes, and the first to desert him, was demanded by the people, and granted. This abominable wretch received the news of his death being required while he was enjoying the waters of Sinuessae, and he cut his throat with a razor. The indulgence of Otho towards those who were his personal enemies, and the change in his habits shown by devoting himself to the administration of affairs, gave people hopes that the emperor would turn out better than was expected. Still these appearances were by many considered deceptive, and there was little confidence in a man who owed his elevation to the murder of Galba, and the violence of the soldiers, whom he was compelled to keep in good humour. Otho was acknowledged emperor by Luceius Albinus, governor of Mauritania (Tac. Hist. 2.58), and by Carthage and the rest of Africa. The legions in Dalmatia, Pannonia, and Maesia took the oath of fidelity to the emperor. He was also recognised by Egypt, by Mucianus in Syria, and by Vespasian in Palestine; by Gallia Narbonensis, Aquitania, and by Spain. But he had a formidable opposition in the legions stationed in Germany on the Rhine, whither Vitellius had been sent to take the command by Galba, in the month of December, A. D. 68. Vitellius was a glutton, a drunkard, and a man of no capacity, but by his affable manners and his liberality he gained the good will of the soldiers who were dissatisfied with Galba. Vitellius had the command of four legions on the Lower Rhine, and two other legions on the upper course of the river were under Hordeonius Flaccus. Some of the Gallic towns also were ill disposed to Galba.

Neither Flaccus nor Vitellius had energy enough to commence a movement: it was begun by Fabius Valens, who commanded a legion in Lower Germany, and stimulated Vitellius to aim at the supreme power. Alienus Caecina, who also commanded a legion in Upper Germany, and was an officer of ability, hated Galba; and thus, before the murder of the aged emperor, every thing was ripe for a revolt in Germany.

Vitellius, who was in the town of Cologne (colonia Agrippinensis), was greeted with the title of imperator, on the third of January, A. D. 69. He accepted the title of Germanicus, but he would not assume that of Caesar. There was a striking contrast between the ardour of the soldiers, who wished to march for Italy in the midst of the winter, and the sluggishness of their newly-elected emperor, who even by midday was drunk and stupified with his gluttonous excesses. But every thing favoured Vitellius. Valerius Asiaticus, governor of Belgica, declared for him, and Junius Blaesus, governor of Gallia Lugdunensis. The troops in Rhaetia and Britain were also on his side. Valens and Caecina were sent forward, each at the head of a large army. The lazy emperor followed at his leisure. Valens had advanced as far as Toul (civitas Leucorum, Tac. Hist. 1.64; D'Anville, Notice de la Gaule, "Tullum"), when he heard of Galba's death, the news of which determined Gallia Narbonensis and Aquitania to declare for Vitellius, though they had taken the oath to Otho. Cluvius Rufus, the governor of Spain, did the same.

Valens advanced by the route of Autun, Lyon, Vienne, and Lucus (Luc), to the foot of the Alps, plundering, and robbing all the way. The march of Caecina was still more disastrous to the country through which he made his way. He readily picked a quarrel with the Helvetii, many of whom were slaughtered, and others were sold as slaves. Aventicum (Avenche), their capital, surrendered, and its fate was left to the mercy of Vitellius, who yielded to the eloquent entreaty of Claudius Cossus, one of the legati who were sent to mollify the emperor. Caecina, while he was still on the north side of the Alps, received intelligence that a body of cavalry on the Po had taken the oath to Vitellius, under whom they had formerly served in Africa. Mediolanum (Milan), Vercellae, and other towns in North Italy, followed this example. Caecina having sent some Gallic, Lusitanian, British, and German troops over the mountains to support his new friends, led his soldiers across the Pennine Alps, through the snow with which they were still covered.

The revolt of Vitellius had not reached Rome at the time of Galba's death. As soon as it was known, Otho wrote to Vitellius, and offered to give him all that he could desire, and even to share the empire with him. Vitellius replied by offers on his part, but they could come to no terms, and both sides made preparation for war. A disturbance was caused at Rome by the praetorian soldiers, who suspected that there was some design against Otho. They broke into the palace, threatening to kill the senators, many of whom were supping with Otho, and with difficulty made their escape. The soldiers penetrated even to the emperor's apartment, in order to be assured that he was alive. The tumult was at last allayed, but the approach of a civil war, from the evils of which the state had so long been secure, caused general uneasiness.

Otho left Rome for North Italy about the fourteenth of March. His brother Titianus remained at Rome to look after the city, with Flavius Sabinus, Vespasian's brother, who was praefectus urbi. Otho had under him three commanders of ability, Suetonius Paulinus, Marius Celsus, and Annius Gallus. He marched on foot at the head of his troops, in a plain military equipment (Tac. Hist. 2.11). Otho's fleet was master of the sea on the north-west coast of Italy, and the soldiers treated the country as if it was a hostile territory. They defeated the Ligurian mountaineers and plundered Albium Intemelium (Vintimiglia). Annius Gallus and Vestricius Spurinna were commissioned by Otho to defend the Po. Spurinna, who was in Placentia, was attacked by Caecina, but succeeded in repelling him and destroying a large part of his force. Caecina retired, but the magnificent amphitheatre which was outside the walls was burnt during the contest. Caecina retreated towards Cremona, and bodies of his troops sustained fresh defeats. Martins Macer, at the head of Otho's gladiators, surprised some auxiliaries of Caecina, who took refuge in Cremona, but Macer from caution prevented his men from following them into the town. His conduct brought suspicion on Suetonius and the other generals of Otho, and Titianus, his brother, was sent for to take the conduct of the war. Caecina made another attempt to retrieve his losses, but hewas beaten by Marius Celsus and Suetonius, who, however, would not allow the men to follow up their advantage ; and that which probably was prudence, became the foundation of a charge of treason against him from his troops.

Valens, who was at Ticinum (Pavia), now joined his forces to those of Caecina, and the two generals, who had been jealous of one another, now thought only of combining to defeat the enemy. Otho's generals advised him to avoid a decisive battle, but his own opinion, and that of his brother and of Proculus, praefectus praetorio, was in favour of bringing the war at once to a close; and this determination ruined the cause of Otho. He was advised to retire to Brixellum (Brescelli), to be out of the way of danger, and he went there with a considerable force. The generals of Vitellius knew the state of affairs in Otho's army, and were ready to take advantage of it. The hostile armies were on the Po. The forces of Otho, under Titianus and Proculus, were marched to the fourth milestone from Bedriacum (Cividale ?), and on their route they suffered for want of water. They had now sixteen miles to march to the confluence of the Adda and the Po, to find the enemy, whom they came up with before they were expected. A fierce battle was fought in which Otho's troops were entirely defeated. It is said that forty thousand men fell in this battle. The troops of Vitellius followed up the pursuit within five miles of Bedriacum, but they did not venture to attack the enemy's camp on that day. On the next day the two armies came to terms, and the soldiers of Otho received the victors into their camp.

Though Otho had still a large force with him, and other troops at Bedriacum and Placentia, he determined to make no further resistance, and to die by his own hand. After settling his affairs with the utmost coolness and deliberation, he stabbed himself. The manner of his death is circumstantially told by Suetonius. His life had been dissolute, and his conduct at the last, though it may appear to have displayed courage, was in effect only despair. He died on the fifteenth of April, A. D. 69, in the thirty-seventh year of his age. His sepulchre was at Brixellum, and Plutarch, who saw it, says that it bore simply his name, and no other inscription. Suetonius, who records every thing, has not forgotten Otho's wig. His hair was thin, and he wore a perruque, which was so skilfully fitted to his head that nobody could tell it from true hair. (Suetonius, Otho ; Plutarch, Otho ; Dio Cassius, lxiv.; Tacitus, Hist. i. ii.; all the authorities are collected by Tillemont, Histoire des Empereurs, vol. i.)