Aurelian's Walls Around Rome

When aurelian built his walls around rome, it was a signal to every other hurban centre to do the same. So now, though the barbarians were still able to cross the borders of the empire with ease, they would no longer find easy pickings on the other side. The romans drew back the practical lines of defence right to their city limits. Zenobia's capture of egypt was absolutely unacceptable. And despite the official partnership that existed between rome and palmira, there was no doubt that the two powers were now headed towards war. Aurelian planned to not just initiate the final conflict, but to win it outright. Palmira would be laid low