M. Brutus to Cicero, written from his camp on 1 July 43 BC — Perseus dateline Scr. in castris K. Quint. a. 711 (43), confirmed by the closing “Kal. Quintilibus ex castris.” The meta entry’s day-precision date is correct.

The letter is a plea on behalf of children, written in the moment when Brutus first suspects that his brother-in-law M. Aemilius Lepidus is about to defect to Antony. Lepidus’s army in Narbonensis has been wavering through May and June; the rumours have multiplied; Brutus knows that if his sister Junia’s marriage to Lepidus turns into the marriage of a public enemy, his nephews will be ruined by the senatorial decree of hostis publicus. He writes to Cicero, head of the senatorial party, to put on the record now, before any vote falls, that he speaks not as a brother-in-law but as the boys’ avunculus (their maternal uncle), and that he considers himself to have succeeded their father in their care. The compression is unusual for Brutus, the language unguarded (“my anxiety and my exasperation,” sollicitudo ac stomachus, are uncomfortably candid). The fear was justified: the news of Lepidus’s junction with Antony reaches Rome on 30 June, the day before this letter is written, and the Senate’s vote declaring him a public enemy will pass on 30 June or shortly after, while this letter is on its way to Rome.