Queensblade

From the back cover of the Popular Library first edition: "In distant Penllyn, a barbaric fate awaits the Princess Gwenlliant. For here it is decreed that every queen must one day slay herself with the sacrificial dagger called Queensblade... Torn by desperation for her mother, whose time has come, and the awesome powers of magic welling within her soul, Gwenlliant will journey to Byzantium. But in this city of glittering towers, her father, Emperor Marric is summoning her to face an even darker destiny. According to the custom of their gods, Gwenlliant must wed her own brother and rule by his side. Now her only hope will lie in the magic that she so fears, the magic that is her legacy, the magic that can free her and her family - and fulfill the glorious dream of the heirs of Byzantium!"