Scholars believe Romans fought in this way: Many queues would advance as a unit, but only the man at the head of each line would actually be fighting, and he for only a few minutes. As he tired, he yielded to the second man in line running to the back of the line. The second soon yielded to the third, and so on. In this way, men regained strength, and at any given moment only relatively fresh troops would be engaged. This deployment was unique in ancient warfare, and consistently effective.
