Roma VI
From Tardis Wiki, the free Doctor Who reference
Roma VI was one of many alternate timelines where the Roman Empire never fell. The head of the Vestal order led the empire, and women, not men, were the sex engaged in politics. Diana was from Roma VI and became its Empress.
It was immediately "threewards" of Roma II and "twowards" of Roma III. (PROSE: Warlords of Utopia)