structural:summarization, structural:expansion, information:filtering
Public life, marriage, and literary career

As a young man, Tacitus studied rhetoric in Rome to prepare for a career in law and politics; like Pliny, he may have studied under Quintilian (c. 35 AD – c. 100). In 77 or 78, he married Julia Agricola, daughter of the famous general Agricola.

Little is known of their domestic life, save that Tacitus loved hunting and the outdoors. He started his career (probably the latus clavus, mark of the senator) under Vespasian (r. 69–79), but entered political life as a quaestor in 81 or 82 under Titus.

He advanced steadily through the cursus honorum, becoming praetor in 88 and a quindecimvir, a member of the priestly college in charge of the Sibylline Books and the Secular Games. He gained acclaim as a lawyer and as an orator; his skill in public speaking ironically counterpoints his cognomen, Tacitus ("silent").

He served in the provinces from c. 89 to c. 93, either in command of a legion or in a civilian post. He and his property survived Domitian 's reign of terror (81–96), but the experience left him jaded and perhaps ashamed at his own complicity, instilling in him the hatred of tyranny evident in his works. The Agricola, chs. 44 – 45, is illustrative:

Agricola was spared those later years during which Domitian, leaving now no interval or breathing space of time, but, as it were, with one continuous blow, drained the life-blood of the Commonwealth... It was not long before our hands dragged Helvidius to prison, before we gazed on the dying looks of Mauricus and Rusticus, before we were steeped in Senecio 's innocent blood. Even Nero turned his eyes away, and did not gaze upon the atrocities which he ordered; with Domitian it was the chief part of our miseries to see and to be seen, to know that our sighs were being recorded...

From his seat in the Senate, he became suffect consul in 97 during the reign of Nerva, being the first of his family to do so. During his tenure, he reached the height of his fame as an orator when he delivered the funeral oration for the famous veteran soldier Lucius Verginius Rufus.

In the following year, he wrote and published the Agricola and Germania, foreshadowing the literary endeavors that would occupy him until his death.

Afterward, he absented himself from public life, but returned during Trajan 's reign (98–117). In 100, he and his friend Pliny the Younger prosecuted Marius Priscus (proconsul of Africa) for corruption. Priscus was found guilty and sent into exile; Pliny wrote a few days later that Tacitus had spoken "with all the majesty which characterizes his usual style of oratory".

A lengthy absence from politics and law followed while he wrote the Histories and the Annals. In 112 to 113, he held the highest civilian governorship, that of the Roman province of Asia in western Anatolia, recorded in the inscription found at Mylasa mentioned above. A passage in the Annals fixes 116 as the terminus post quem of his death, which may have been as late as 125 or even 130. It seems that he survived both Pliny (died c. 113) and Trajan (died 117).

It remains unknown whether Tacitus had any children. The Augustan History reports that Emperor Marcus Claudius Tacitus (r. 275–276) claimed him for an ancestor and provided for the preservation of his works, but this story may be fraudulent, like much of the Augustan History.