The Armed Force
In the history of Roman swords, the army started with the drafting of middle-class families to join the Legion, the smallest military unit composed of about 5,000-strong infantry and 300-strong cavalry. Such practice was influenced from Greek sword fighting, as well as from Celtic sword fighting.
The legion being a heavy infantry, it was costly for a soldier to buy his own shield, Roman short sword, and other war weaponries. This would be worth it, as distinguished soldiers were awarded through bounty, promotion of rank, and appointment to political posts. Later on, as the empire evolved, the Legion was professionalized, soldiers were paid, and anyone could be drafted regardless of their financial position.
Roman training
A legionnaire had to go through intense physical, mental, and military drills before being admitted to the unit. The daily regimen of a soldier was grueling: they started their morning with a march to build up endurance; they carried weights in running, walking, or swimming drills to build up strength and stamina; and they needed to endure hunger and thirst to prepare them in times when supplies were cut off.
Roman sword fighting techniques
The Roman army was considered the best of its days, and it heavily used military science to defeat enemies. Compared to the armies of the barbarians, it is an army that knew exactly what to do at any point of the fight. Its complex range of army formations, attack stances, and use of siege weapons made it succeed in many military campaigns and colonize tribes in ancient Europe. (see What is a Roman sword for details of the armor and weapons)
The use of Roman swords was well coordinated. Weapons training required soldiers to get accustomed to the heavy shield, to know how to use the weapon, to predict timing, and to deliver blows without exposing oneself to danger.