Imperial

Forbidding but inert, Galba only shows signs of life and interest when money and discipline are concerned. If Tacitus seems over-harsh, there are the anecdotes of Suetonius for corroboration. Galba used to say that a man ought not to be called to account for what he does after hours [snobbery, cruelty, avarice, conceit, gluttony, homosexuality].  That was not the opinion held at Rome in the days of the Scipiones.

 Otho by contrast - affable, pliant, and corrupt - belonged to his own epoch, a choice luxury product of the Neronian court. It  is on Otho when he resolves to end his life that the historian lavishes the resources of talent and sympathy, with the setting of a drama, with magnificent eloquence in farewell, with noble words of consolation for friends and family - and no hint that the capitulation of his forces is imminent or already transacted. What draws Tacitus is manifest. Not merely the opportunity to portray a theatrical suicide, such as the taste of the Romans took delight in, but a suicide more truly to be commended than when a good man took his own life in ostentatious rectitude [the proscribed opening, closing, opening their veins before an audience of friends, admirers, family], but with no advantage to the Commonwealth. Otho's resolution averted any further shedding of Roman blood in civil war. Other rulers fail by contrast. Nero could not summon energy for action, or dignity at the end. Vitellius, when his armies were lost, sank into lethargy like a fat animal. He let the futile struggle go on, incompetent even to manage aright his own abdication. The artifice of Tacitus is patent. No deception, no conflict with what the historian has previously revealed about the character, actions, and repute of Otho. Tacitus is quite clear. He sets it on record that Otho had been feared and detested much more than Vitellius.

[...]

Detesting civil strife and suspicious of power and success, Tacitus achieves a sombre and savage impartiality in the portrayal of the crime and violence of the year 69. Tacitus is harsh and bitter, offering no consolation anywhere. His despair is engendered by the contrasts between word and fact, between ambitions and achievement, by the tragic vicissitudes of men and governments. It has yet to be proved that acerbity or gloom is detrimental in an historian.

Ronald Syme "Tacitus" (1958) vol 1 pp205-206

Above: Nero; Galba; Otho; Vitellius.