The good sense of Vespasian engaged him indeed to embrace every measure that might confirm his recent and precarious elevation. The military oath, and the fidelity of the troops, had been consecrated, by the habits of a hundred years, to the name and family of the Cæsars; and although that family had been continued only by the fictitious rite of adoption, the Romans still revered, in the person of Nero, the grandson of Germanicus, and the lineal successor of Augustus. It was not without reluctance and remorse, that the prætorian guards had been persuaded to abandon the cause of the tyrant. 34 The rapid downfall of Galba, Otho, and Vitellus, taught the armies to consider the emperors as the creatures of _their_ will, and the instruments of _their_ license. The birth of Vespasian was mean: his grandfather had been a private soldier, his father a petty officer of the revenue; 35 his own merit had raised him, in an advanced age, to the empire; but his merit was rather useful than shining, and his virtues were disgraced by a strict and even sordid parsimony. Such a prince consulted his true interest by the association of a son, whose more splendid and amiable character might turn the public attention from the obscure origin, to the future glories, of the Flavian house. Under the mild administration of Titus, the Roman world enjoyed a transient felicity, and his beloved memory served to protect, above fifteen years, the vices of his brother Domitian. 34 (return) [ This idea is frequently and strongly inculcated by Tacitus. See Hist. i. 5, 16, ii. 76.] 35 (return) [ The emperor Vespasian, with his usual good sense, laughed at the genealogists, who deduced his family from Flavius, the founder of Reate, (his native country,) and one of the companions of Hercules Suet in Vespasian, c. 12.]