Etruscans

In the early days of the Roman Empire, as the Romans are expanding their rule and the noble Etruscan civilization in Italy is waning, a young Etruscan noblewoman is violated by a renegade supernatural being. Accidentally impregnated, she bears a child who is partly supernatural and grows to manhood in only six years. Separated from his mother, he travels to Rome and is adopted by a businessman as his son. His name is changed to Horatius. But all the while, his demon father is seeking him in order to kill him, for Horatius is a conduit through which the demon might be found and magically destroyed. Etruscans is epic, magical fantasy on a par with David Drake's Lord of the Isles series.