Final answer:
The Roman army was characterized by strict discipline, professional soldiers, and standardized equipment, including a gladius and scutum. The legion was the backbone of the military, with each legion a self-sufficient unit capable of independent operations or joining larger forces. Over time, the professional army faced increased strain due to extended campaigns and the costs associated with managing a vast empire.
Step-by-step explanation:
The Roman army's fighting style was highly disciplined, with an emphasis on unit cohesion and readiness for battle. Soldiers were expected to march over 20 miles a day with heavy packs and faced severe discipline for any dereliction of duty. The army transitioned from a volunteer force in early Rome to a professional standing force by the time of the empire, eventually consisting of the legion as the cornerstone. Each legion, numbering about five thousand soldiers, was commanded by a legate and included craftspeople and builders. The standard equipment of a legionnaire featured a short sword known as a gladius, a large rectangular shield called a scutum, a helmet with a crest and a feathered visor, and leg greaves for protection.
Auxiliary forces fought with their own weapons and tactics, and soldiers in the regular legions were trained for formation fighting, first throwing javelins and then engaging with their gladius. The distribution of wealth from conquests and promised land were incentives for service. During campaigns, the legion acted as a self-sufficient unit that could also be part of a larger invasion force.
Despite the depiction of Roman military might in art, the empire faced constant invasions and conflicts that challenged its sustainability. The cost of running an expansive military in prolonged conflicts strained the Roman Empire's resources, contributing to difficulties in its later years.