By the time of Trajan (), the medical corps was well on the way to being an organized machine. At this time, physicians were attached to nearly every army and navy unit in all the Roman military. By this time the army was massive, consisting of twenty-five to thirty legions, each of which contained nearly 6,000 men. Each one included both soldiers and physicians. Despite these large numbers there was still no formal requirements for being a physician. At this point all physicians were either self-taught or learned their trade through an apprenticeship. Despite this, there was an attempt at organization, as the army did have a medical manual that was passed out to its physicians. The medici were used on both the front line as emergency care providers and in the rear as the main physicians. The capsarii' were mainly used as the front line care providers and bandages, but also assisted the medici behind the lines.
