Chapter 2 was originally called ‘Dinner with the Camp Commander’. But on learning more about the structure of the Roman Legion, I have renamed it ‘Dinner with the First File’. First File was the designation of the longest-serving Commander, although as a career officer he was of lower rank than the young noblemen who did a year or two of military service on their way to careers in politics. The First File was the man who actually ran the Legion. (Tinkering with a completed novel is easier to do when it is self-published rather than in the hands of publisher, but it creates its own confusions…)
In this chapter, Matthew has dinner with the main characters from the Roman side of the novel (apart from Pilate): his old friend Longus, now the de facto head of the Tenth Legion Fretensis; two other senior career officers, Caninus and Purpureo; two enlisted men, Buteo and Bibaculus; and the excitable young Jewish civilian, Paulus.
Apart from introducing key characters, the purpose of the chapter is to begin the depiction of the cultural gulf between Rome and Israel, a gulf that was unbridgeable between the military might on one side and the religious conviction on the other. About the only thing the societies had in common was the unthinking male chauvinism that was the worldwide norm.
The dinner menu itself shows the gulf: the Romans basically ate everything they came across, and to eat at their table was to renounce Jewish purity.
The process of serving wine is included as being interesting in itself – and it also suggests how easily Jesus’ first “miracle” could have been worked at the marriage feast in Cana, an event that is remembered but not shown in the novel.
The common interest of the dinner party (all men) is Mithraism, the mystery religion popular in the army. Even today not a lot is known of Mithraism, but enough to see that it was the origin of a lot of the imagery that St. Paul used in creating Christianity. For Paul to have invoked that imagery, he must have been familiar with it, which implies association with the Roman army. It is easy to introduce him here. But this is a work of fiction – there is no historical reason for thinking that he and Matthew ever met.