Kind of, though it only covered what are Fantasy Spain and Italy and lasted for less than a hundred years, as Roman Empires go it's not much of a one.
The Reman empire might not even be a thing in Warhammer canon, because a while back I did a deep dive, and the only legitimate source I could find was a single sentence in a spin off product published in '89.
Holy shit that's older than I am
Edit: I found a copy of the rule book. The part about the Reman Empire is mostly about how Khorne corrupted it's people, and then sent demon armies to destroy it. Solkan awoke during the war, and attempted to fend off the invaders. His amulet—the macguffin of the adventure—was broken in the fighting, and the four pieces were scattered across the land. Most of the pieces have fallen into the hands of the Skaven, and the heroes have to battle Clan Mors and Rictus warriors supported by Eshin assassins, Pestilens monks, and Skyre Sorcerers (including a Skyre "White Skaven Sorcerer").