In the early days of the republic the Romans had to constantly protect themselves from rival Italian tribes. They found that the best way to defend was to attack.

In this way the surrounding tribes like the Samnites were conquered. Then the Etruscans to the north and the Greek colonies to the south  were overrun. By the middle of the 3rd century BC  Rome dominated all Italy.

  At this time the Roman soldier was simply a free man fighting to defend his family and farm , a bit  like the Greek hoplite.  Like the hoplite he had to provide his own armour. He fought in a phalanx.

Then came a series of wars  against the Carthaginians in Africa  (the Punic Wars). They lasted for a hundred years (until 146BC) and left Rome in control of  the Mediterranean, North Africa and Spain. Geece was conquered at the same time.

The Roman soldier  became a  paid  professional , well-trained  and disciplined. His armour and weapons were provided  for him. The picture shows what he carried into battle. He was expected to walk 40  kms a day  carrying 35 kgs of equipment (change of clothes, two weeks supply of cereals, cooking pot, spade, two fencing posts , a hammer, saw and coil of rope) and then build a defended camp in the evening.

Each legionary was in a century of 80 men. 6 centuries formed a cohort and 10 cohorts formed a legion.  The Roman army was not very big , only about 30 legions but conquered men often were added on as auxiliaries to fight as archers, cavalry-men or  stone-slingers.  After  the conquest of Gaul , the Franks became excellent soldiers in the Roman army.