(Caius Cornelius), a celebrated Roman historian, and one of the greatest men of his time, appears to have been born about the year of Rome 809 or 810, and applied himself early to the labours of the bar, in which he gained very considerable reputation. Having married the daughter of Agricola, the road to public honours was laid open to him in the reign of Vespasian; but during the languishing and capricious tyranny of Domitian, he, as well as his friend Pliny, appears to have retired from the theatre of public affairs. The reign of Nerva restored these luminaries of Roman literature to the metropolis, and we find Tacitus engaged, in the year 850, to pronounce the funeral oration of the venerable Virginius Rufus, the colleague of the emperor in the consulship, and afterwards succeeding him as consul for the remainder of the year.

The time of his death is not mentioned by any ancient author, but it is probable that he died in the reign of Trajan.

His works which still remain are, 1. Five books of his History. 2. His Annals. 3. A Treatise on the different Nations which in his time inhabited Germany; and, 4. The Life of Agricola his father-in-law. There is also attributed to him a Treatise on Eloquence, which others have ascribed to Quintilian. The Treatise on the Manners of the Germans was published in 851.—In the year 853, Pliny and Tacitus were appointed by the senate to plead the cause of the oppressed Africans against Marius Priscus, a corrupt proconsul, who was convicted before the fathers; and the patriot orators were honoured with a declaration that they had executed their trust to the entire satisfaction of the house. The exact time when Tacitus published his history is uncertain, but it was in some period of Trajan's reign, who died suddenly, A. U. C. 870, A. D. 117.—The history comprises a period of 27 years, from the accession of Galba, 822, to the death of Domitian, 849. The history being finished, he did not think he had completed the tablature of slavery; he went back to the time of Tiberius; and the second work, which, however, comes first in the order of chronology, includes a period of 54 years, from the accession of Tiberius, 767, to the death of Nero, 821: this work is his "Annals."

It is remarkable, that princes and politicians have always held the works of Tacitus in the highest esteem; which look as if they either found their account in reading them, or were pleased to find courts, and the people who live in them, so exactly described after the life as they are in his writings. Part of what is extant was found in Germany by a receiver of Pope Leo X. and published by Beroaldus at Rome in 1515. Leo was so much charmed with Tacitus, that he gave the receiver a reward of 500 crowns; and promised not only indulgences, but money also and honour, to any one who should find the other part; which it is said was afterwards brought to him. Pope Paul III., as Muretus relates, wore out his Tacitus with much reading it; and Cosimo de Medicis, who was the first great duke of Tuscany, and formed for government, accounted the reading of him his greatest pleasure. Muretus adds, that several princes, and privy-counsellors to princes, read him with great application, and regarded him as a sort of oracle in politics. A certain author relates, that Queen Christina of Sweden, Sweden, though extremely fond of the Greek tongue, which she made "the diversion of her leisure hours, was not restrained by that from her serious studies; so she called among others Tacitus's History, some pages of which she read constantly every day." Lastly, our late Lord Bolingbroke, an authority surely of no mean rank, calls him, "a favourite author," and gives him manifestly the preference to all the Greek and Roman historians.

No author has obtained a more splendid reputation than Tacitus. He has been accounted, and with good reason, the most cultivated genius of antiquity; and we must not seek for his parallel in modern times. It is impossible not to admire and recommend his intimate knowledge of the human heart, the spirit of liberty which he breathes, and the force and vivacity with which he perpetually expresses himself. The reader of taste is struck by the greatness of his thoughts and the dignity of his narration; the philosopher by the comprehensive powers of his mind; and the politician by the sagacity with which he unfolds the springs of the most secret transactions. Civil liberty and the rights of mankind never met with a bolder or a more able affirmer: servitude, debasement, and tyranny, appear not in the writings of any other author in juter or more odious colours. He has been censured as obscure; and indeed nothing can be more certain than that he did not write for the common men of men. But to those who are judges of his compositions, it is no matter of regret that his manner is his own, and peculiar. Never were description and sentiment so wonderfully and so beautifully blended; and never were the actions and characters of men delineated with so much strength and precision. He has all the merits of other historians, without their defects. He possesses the distinctness of Xenophon without his uniformity; he is more eloquent than Livy, and is free from his superstition; and he has more knowledge and judgment than Polybius, without his affectation of reasoning on every occasion.

One of the best editions of the works of Tacitus was published at Paris by Brotier, in 4 vols 4to. There have been four translations of his works into English; the first by Greenway and Sir Henry Saville, in the reign of Elizabeth; the second by Dryden and others; the third by Gordon, which is remarkable for affectation of style, though some think it bears a striking resemblance to the original; and the fourth and best by Murphy, in 1793, in 4 vols 4to.