The Romans were a people who were raised to fight. After basic education, the males were sent for a two year long service in the army. After the two year hiatus in the army, they could opt to come back to Rome or they could continue being a soldier. 

The Roman military engaged in military campaigns for all of Rome's history, and focused on expanding Rome's territory. The Roman army was mostly compiled of civilians who would rather serve in the army than till the fields back home. It was quite the professional force, consisting of over 700,000 men at the height of Rome's reign. The army would split into two, and would fight two military campaigns at the same time so as to maximize effectiveness.

The Romans favored teamwork and cohesiveness as a unit over rash charging and flailing around with a sword. They emphasized that the shield was the best weapon a soldier could have. They also stressed that ducking behind your shield and waiting for an opportune moment to stab someone was better than making wild slashing motions with your blade. In military training, they used harsh training methods in order for the men to bond and have a sense of teamwork.

Roman military equipment was quite useful in many situations. A Roman soldier would carry two javelins, a short blade called a gladius, and a shovel. Part of the Roman army's effectiveness was the ability to build fast and to use resources to their maximum effectiveness. Roman soldiers were taught that a shovel might save your life, but a sword wouldn't.

Roman units of solders were called legions, and within legions, there would be smaller units called cohorts. Each individual legion would have a banner, and various titles would be given to the legion if it performed valiant acts of bravery. 

Roman military tactics involved getting rid of a region's local warlord, and replacing him with a puppet to govern in the interests of Rome. In battle, the Romans had various formations, such as the testudo. The Romans also adapted fairly well to other styles of formations, including local and foreign styles.