Gallia Narbonensis
The province of his birth remains unknown, though various conjectures suggest Gallia Belgica, Gallia Narbonensis or Northern Italy. His marriage to the daughter of Narbonensian senator Gnaeus Julius Agricola implies that he came from Gallia Narbonensis. Tacitus' dedication to Lucius Fabius Justus in the "Dialogus" may indicate a connection with Spain, and his friendship with Pliny suggests origins in northern Italy. No evidence exists, however, that Pliny's friends from northern Italy knew Tacitus, nor do Pliny's letters hint that the two men had a common background. Pliny Book 9, Letter 23 reports that, when he was asked if he was Italian or provincial, he gave an unclear answer, and so was asked if he was Tacitus or Pliny. Since Pliny was from Italy, some infer that Tacitus was from the provinces, probably Gallia Narbonensis.