The Roman army survived for centuries through Rome’s Kingdom, Republic and both Empires. Many historians divide the development of Rome’s army into eight phases.
1) The Early Roman army lasted until 300 BCE and existed throughout the Kingdom and the early Republic. This was based on a conscription system.
2) After the Republic formed, the Roman Army of the mid-Republic lasted from 300-107 BCE and experienced a transition from a temporary force based on short-term conscription to a standing army.
3) The Roman Army of the Late Republic lasted from 107-30 BCE continued this transition from the temporary force of the mid-Republic to the mainly volunteer, professional standing forces of the imperial era. Julius Caesar’s works are the main literary source for the tactics of this phase.
4) After the Republic fell, the Imperial Roman Army existed from 30 BCE - 284 CE and finally entirely replaced the citizen-conscription. Volunteers served 20-year terms as standard minimums. These legions consisted almost entirely of heavy infantry.
6) The Late Roman Army lasted from (284 - 476 CE)
7) The East Roman Army lasted until 641 CE after the fall of the Western Empire.
8) Palaiologan Byzantine Army
As ancient Rome evolved from the Kingdom to the Republic and both Empires, the army gradually increased the manpower, training and weaponry available. This civilization thrived primarily because of the huge military successes they consistently had along the Mediterranean. This expansionism led to them them becoming one of the largest empires in the ancient world.
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