Roma Mater

Book one of the King of Ys series: Blending fantasy, history, and adventure, the epic story of Ys begins as the Roman Gratillonius finds himself thrust into the highest seat of power
In the waning days of the Roman Empire, Magnus Maximus sends his prefect Gratillonius to western Gaul and the faraway land of Ys, a place shrouded in legend and ruled by a cruel and tyrannical king. When the sovereign challenges Gratillonius to a duel, the envoy from Rome emerges victorious and claims the throne as the new king of Ys, inheriting a land whose religion, culture, and history are entirely foreign. He also gains the former king's nine wives, the Gallicenae, a powerful group of women to whom he must appear equally devoted despite his growing feelings for one in particular. As he adjusts to his new role as ruler of Ys, Gratillonius must fight to keep his strange new country on its feet while the rest of the Roman Empire begins to crumble around him.

Roma Mater is the first book in Poul and Karen Anderson's King of Ys series, which continues with Gallicenae.