Domnei by James Branch Cabell

It is a tale which they narrate in Poictesme, telling how love began between Perion of the Forest, who was a captain of mercenaries, and young Melicent, who was daughter to the great Dom Manuel, and sister to Count Emmerick of Poictesme. They tell also how Melicent and Perion were parted, because there was no remedy, and policy demanded she should wed King Theodoret.

And the tale tells how Perion sailed with his retainers to seek desperate service under the harried Kaiser of the Greeks.