Decimus Marcus Brutus, aka Mouse. The narrator, and one of those responsible for stabbing Caesar to death (don't worry, this isn't giving the story away). The general's perspective is so humble and inward-looking that I soon felt I knew him as a friend. Every relationship has been masterfully crafted, and Caesar himself seems a god-incarnate - just right. The grim inevitability of it all held me until the last - Mouse both loved and hated Caesar because he knew just as Caesar was the cause of his rise, he would be the man behind his fall.
Be aware that sex is very prevalent, generally dealt with well in my opinion; and that although this novel has only one swear word (as far as I can remember - possibly discounting the sex), it is the single best use of an expletive I have ever read.
But then who ever said in Rome they were abstinent, tea-total and kind-mouthed? Massie probably gets it just right, a difficult task.