The younger Pliny was seventeen when Vesuvius erupted in A.D. 79, according to his Epistulae (Epistles, A.D. 103-A.D. 109, 6. 20), a fact that situates his birth in late A.D. 61 or early A.D. 62. He was born in Comum (modern Como), the son of Lucius Caecilius. His father's family, like that of his mother (the Plinii), were wealthy and apparently well-connected municipal landowners. His parents had already divorced by the time of his father's death. His guardian was Verginius Rufus, the general who crushed the revolt of Vindex in A.D. 68, was twice consul, and twice refused to be hailed as emperor. Pliny was brought up by his uncle, Pliny the Elder, who bequeathed his nephew his property and his name: young Caecilius became Gaius Plinius Caecilius Secundus, Pliny the Younger.

Pliny was at once docile and ambitious: at age fourteen he composed a Greek tragedy. In...