I tried to read McCullogh's series on Rome and never finished the very first one. It was historically well researched and very well founded, but I just couldn't get into it as it was just too damned long. If you want to try some equally accurate novels, try Johm Maddox Roberts' SPQR series of whdunnits featuring Decius Caecillius Metellus the Younger, a scion of one of the oldest of the Senatorial families that were of the "Optimates" party along with Sulla and Cicero. Decius is a very snarky soul and his view of Roman politics in the 1st Century BCE is very funny as well as being spot-on historically. Another covering the same period, but from the other end of society, is Stephen Saylor's "Roma Sub Rosa" series featuring Gordianus the Finder. Think of Mike Hammer set in Rome of the 1st Century BCE. The third series is Lindsey Davis's Marcus Didius Falco series. Falco is a private eye operating during the principate of my favorite first citizen, Vespasian. Her writing is unaplogetically British and sometimes you feel as if she is writing about the London underworld rather than that of Ancient Rome, but the novels are great. Paul Doherty has also written 3 or 4 set in Ancient Rome. Three of them, Murder Imperial, Queen of the Night, and Song of the Gladiator, are about Helena, Constantine I's mother and her spies, the agentes in res, who formed the political muscle to underlay Constantine's unquestioned military success. One of them, her "Little Mouse," Claudia, is the hero of the three stories and they all involve Helena and Claudia and the emerging Christians as a political force in Rome. Doherty wrote another, Domina about Nero's mother, Agrippina the Younger, and it is a very sympathetic view of a woman whom history generally sees as a manipulative bitch who got what she deserved when her son had her murdered. I rather enjoyed it.
Trying to Walk in the Light, Hugh
1 John 1:5