She was in Aetius’s chalet, one of a row in this little community in the lee of the Wall. It wasn’t grand, just a hut of four rooms built of wattle and daub to the rectangular Roman plan. But it had a tiled floor and a deep hearth, and was cozy and warm. It had been erected when long-stay soldiers had first been allowed to marry and raise families. It was here, during an earlier tour of duty with the border troops, that Aetius had brought his bride Brica, and here that Julia, Regina’s mother, had been born.

Its centerpiece was the lararium, the family shrine that Aetius and Regina had built together after their flight from the villa. The three crudely carved matres in their hooded cloaks sat at the center of a little circle of gifts of wine and food. But this was a soldier’s shrine, and there were also tokens to such abstract entities as Roma, Victoria, and Disciplina, as well as a coin bearing the head of the latest Emperor anybody had heard of, Honorius.

And it was in his chalet that, at Aetius’s insistence, Regina had continued her education. He expected her to become fluent in both her native language and in Latin—and to know the difference; Aetius despised what he called the “muddle,” the patois of Latin-flavored British much favored by the ordinary people of the behind-the-Wall community. He had her read Tacitus and Caesar, historians and emperors and playwrights, from his store of fragile, ancient papyrus scrolls. She learned to write with styli on tablets of wax on wood, and with ink made of soot and a pen of metal. Later, he promised, he would train her in the art of rhetoric. But he believed in combining the best of the British and Roman traditions, and he also had her memorize long sagas of heroes and monsters in the old British style.

“ ‘At present, victor and vanquished enjoy peace and the imperial civilization under the same law on an equal footing. Let your experience of the alternatives prevent you from preferring the ruin that will follow on revolt to the safety that is conferred by obedience . . .’ “

There was some disturbance outside. Shouting, what sounded like singing. No doubt the soldiers were getting drunk again. But Aetius didn’t react, and Regina knew she was safe with him.

Aetius sat in his favorite basket chair, sipping beer. “Yes, yes . . . the same law on an equal footing. The law is above all of us—the landowners, the senators, even the Emperor himself, whoever that is right now. That is the genius of the old system, you see. It doesn’t matter who is in charge. It is the system itself that has spread so far and sustained itself, even though we have had soldiers and administrators and even emperors chosen from among those who would once have been called barbarians. The system persists, while we come and go.”