M. Caelius Rufus to Cicero, the last letter of the correspondence to survive (Perseus: Scr. Romae vel ex. m. Ian. vel m. Febr. a. 706 (48); the Perseus dateline records the Roman tradition, but the contents make plain that Caelius is writing not from the city but from the Caesarian camp, probably soon after the close of the Ilerda campaign and the surrender of Pompey’s Spanish armies). The civil war that the previous letters in book 8 had watched gathering has now broken open. Cicero, after months of agonised hesitation, finally crossed to Pompey in Greece in the summer of 49; Caelius, the protégé of his early career and his political ally through the long Cilician correspondence, took the other road and went to Caesar.

The note is brittle, accusatory, and unmistakably Caelian: a wishing-aloud rather than a considered argument, all the rapid-fire flexes of the gossip-letters now turned to recrimination. He half-regrets having been at Formiae, not Spain, when Cicero set out for Pompey — as if distance alone would have spared him the choice he made; he blames Curio, whose friendship pulled him by degrees into “this ruined business” (hanc perditam causam — the very word Cicero used in private of the Caesarian side); he charges Cicero himself with having neglected the duty of a friend on that night ride to Ariminum, when Caelius came to him on his way to Caesar’s camp and Cicero was full of peace-errands and grand citizenly poses, but gave the younger man no counsel that would have held him back. The second paragraph turns to bitter analysis: he does not lack faith in the Caesarian cause, he says, but he loathes the men around it; the towns are Pompeian through and through except for a handful of money-lenders; he has been working to make the people Caesar’s, and means to make Caesar’s side win in spite of itself. The piece is heavily corrupted in the manuscripts, and three short phrases are bracketed [corrupt] in the translation; the sense, even so, is the unmistakable sound of a young politician who has chosen wrong, knows it, and is reckoning publicly with the friend whose advice he failed to ask. Within months Caelius would quarrel with Caesar over his debt-relief politics, raise a revolt with Milo in Italy, and die there.