MINOR MILITARY SETBACK
A vexhilation of one of Quintus Alexander's legions is defeated by Diodoros, son of Menadides; a minor setback.
Essentially most characters would only need to know things between 50CE through to the current time.
AeRo is mostly AU after Caligula. However, the births of a few important dates were put in place to assist in working out ages, etc.