Madonna of the Dark by Elaine Moore

"Across three continents and three centuries, undying love is a bittersweet perfume enshrouding Victoria MacKay. Compelled to love the vampire, Johann Nikolai Valfrey, Victoria emerges from their evil union a being too glorious for mankind. The clash of her vampire nature and the unbridled gifts of her Celtic bloodline make Victoria more than human and more intimately bound to the living than the undead. She is alternately led and pursued by these forces halfway round the world through great changes in history and three hundred years of dark desire." (summary from Amazon.com)

Paperback Info: ISBN 1928704026, Authorlink, 1999