L. Munatius Plancus to Cicero, written in the territory of the Allobroges at the end of April 43 BC — Perseus dateline Scr. in Allobrogibus ex. m. Apr. a. 711 (43). Plancus has crossed the Rhone and is on the road to Mutina, his brother sent ahead with three thousand horse, when news reaches him in mid-march of the battle at Forum Gallorum and the relief of D. Brutus from the siege of Mutina. The letter is the report he sends back from the turning point: Antony is on the run, the question is now where he is heading, and the answer — that he has only Lepidus and Lepidus’s army left to him — is precisely the answer that lands the whole problem on Plancus’s desk.

The opening section returns the warmth of Cicero’s ad Fam. 10.10, the previous letter in the correspondence and the one Plancus is now answering. Cicero had done him magna officia “great services” in the Senate — proposals with unlimited gifts (the first decree of honours, moved while the case was still hypothetical), later motions trimmed to the moment, an unbroken speech on his behalf, and public quarrels with detractors. Plancus disclaims any prospect of repaying these and accepts Cicero’s own formula: it is enough that he remember them. The closing image of Cicero as the man who must tuum munus tuere, “look after your own creation,” is more candid than it sounds; Plancus is asking Cicero in the Senate to defend the loyalist Plancus he has just publicly vouched for.

The military middle section is the practical heart of the letter. Plancus has halted in the country of the Allobroges to keep his options open: if Antony comes through stripped of forces, Plancus can handle him alone even should Lepidus’s army take him in; if Antony brings serious forces, and especially if the Tenth Legion (Caesar’s old veterans, whom Plancus had been instrumental in calling back to the colours) reverts to its former allegiance, then Plancus needs the Senate’s armies sent across to him from Italy. The third section is the political overlay: Plancus is working on Lepidus, with his brother and Laterensis and Furnius as intermediaries, and is willing to work even with personal enemies for the sake of the cause. The last clause — “and if I gain nothing by it, I shall still satisfy you, none the less, with the greatest spirit and perhaps with the greater glory to myself” — carries the shape of a man who already sees how the gambit may fail. Within weeks Lepidus will join Antony, and Plancus, after a further hesitation, will follow.