Appian of Alexandria Civil Wars 2.16.113

[113] While the talk about the kingship was going on, and just before there was to be a meeting of the Senate, Cassius met Brutus, and, seizing him by the hand, said, What shall we do in the senate-house if Caesar’s flatterers propose a decree making him king? Brutus replied that he would not be there. Then Cassius asked him further, What if we are summoned there as praetors, what shall we do then, my good Brutus? I will defend my country to the death, he replied. Cassius embraced him, saying, Which of the nobility will you allow to share your thought? Do you think that artisans and shopkeepers have written those clandestine messages on your tribunal, or rather the noblest Romans, those who ask from the other praetors games, horse-races, and combats of wild beasts, but from you liberty, as a boon worthy of your ancestry? Thus did they disclose to each other what they had been privately thinking about for a long time. Each of them tested those of their own friends, and of Caesar’s also, whom they considered the most courageous of either faction. Of their own friends they inveigled two brothers, Caesilius and Bucolianus, and besides these Rubrius Ruga, Quintus Ligarius, Marcus Spurius, Servilius Casca, Servius Galba, Sextius Naso, and Pontius Aquila. These were of their own faction. Of Caesar’s friends they secured Decimus Brutus, whom I have already mentioned, also Gaius Casca, Trebonius, Tillius Cimber, and Minucius Basillus. ¹