This is another author who is a favourite of mine, though admittedly I have not read any of the new series she's begun about Rome. The epic series I love so much is about the life of one of Britain's greatest warrior queens: Boudica. The series begins with her childhood and takes us right through to her death.
Dreaming the Eagle
Dreaming the Bull
Dreaming the Hound
Dreaming the Serpent Spear
Admittedly, Dreaming the Hound doesn't deal with her directly, but the character it does deal with is pivotal to the final book of the series so I don't believe it takes away from the over-all story.