The Golden Slave by Poul Anderson

This might have happened. The Cimbri are still remembered by the old district name Himmerland. Plutarch describes the battle at Vercellae, which took place 101 B.C., and its immediate aftermath. Other classical writers, such as Tacitus and Strabo, and a treasure of archeological material enable us to guess at the Cimbri themselves. Apparently they were a Germanic tribe from Jutland, with some elements of Celtic culture; by the time they reached Italy they had grown into a formidable confederation.

The Cimbrian hordes galloped across the dawn of history and clashed in screaming battle against the mighty Roman legions.Led by their chief, Boierik, and his son, Eodan, the hungry and homeless pagan tribes hurled back the Romans time after time in their desperate search for land. But for all the burning towns, the new-caught women weeping, the wine drunk, the gold lifted, the Cimbri did not find a home. And now it was over. At Vercellae the Roman armies shattered them completely. Only a few survived—and for them death would have been more merciful.​ Eodan, the proud young chieftain, had been caught and sold into slavery, his infant son murdered and his beautiful wife, Hwicca, taken as a concubine.

But whips and slave chains could not break the spirit of this fiery pagan giant who fought, seduced and connived his way to a perilous freedom to rescue the woman he loved.