Young aristocrat Anthony Raine returns home from India to find the farmers of Pembrokeshire protesting about the rates of a tollgate run by The Whitman Turnpike Trust, headed by the drunken Lord Sarn. So Raine dons a mask and, calling himself Rebecca, instructs his followers to dress as women as they attack the tolls, leading the common people to victory over their masters.

In the 10th century, Jestyn, a young orphan with a Celtic father and Saxon mother, is captured by Vikings and sold as a slave in Dublin; his master, Thormod, frees him for good service and Jestyn sails to Denmark on one of his longships. On returning to Ireland, he finds Thormod's father murdered. Jestyn and Thormod swear to avenge him, and the search for the killers leads them to the Baltic and Kiev. In Constantinople, Jestyn, still searching for his roots and his identity, discovers a totally unknown Byzantine world. Drawn in, he remains there.