Forum Romanum
Outlines of Roman History: The Military System
The strength of the organization of the Roman army was the key to its success. Read about the composition of the army, Roman military strategy, and weaponry. The road system allowed the army to reach every part of Italy easily.
Other
Digital Attic: The Military Affairs of Ancient Rome
Everything you want to know about the Roman army is discussed and explained here in great detail. This covers all aspects of the Julius Caesar's legions in his invasion of Gaul.
Franco Cavazzi
Roman empire.net: Roman Army Pictures
This site from Roman-Empire.net provides an illustration and brief description of the types of Roman soldiers, Roman forts, and siege engines.
Curated OER
A Hand Cranked Catapult; Manuballista
Article examines the technology the Romans brought with them when they invaded Britain in AD 43. From their missile-throwing machines to surveying materials and signaling flags, it's easy to see how the Romans quickly overtook the native...