Why did the Romans change battle tactics?

Answer

Both the armor and battle formations of the Roman armies changed, albeit slowly. A few reasons:

• of course the confrontation with other opponents, from which lessons were learned: from the Greek-Macedonian phalanxes (closed ranks of pikemen) to the cavalry troops of Carthage (elephants!), to the Germanic tribes…
• the simple growth of the army apparatus, which, in addition to the solid core of heavy infantry, gave rise to specialized auxiliaries: archers, light infantry, engineers, scouts, siege troops, border guards…
• and also the incorporation of auxiliaries of foreign origin, who brought their own weapons and tactics into the Roman army.

In terms of tactics, for example, at the battle of Zama, Scipio Africanus took a lesson from his opponent Hannibal: instead of attacking in three impenetrable lines, he deployed his Roman troops in one very wide line, which allowed him to encircle and trap the opponent. Tried and tested tactics were also found not to be foolproof: the famous “tortoise” trick (testudo) did not work against a combination of archers and swift cavalry, as in the battle of Carrhae.

The armor changed, as you can see in every Roman museum, from chainmail (lorica hamata – perhaps borrowed from the Celts) to the typical armor is strip (lorica segmentata), from an oval shield (clipeus) to the typical curved, man-sized rectangle (scutum), and a huge variety of helmet types.

There were also evolutions in terms of weaponry. It is not true that the long javelins (pila) disappeared, they were added. They were given ‘Spanish’ short stabbing swords (gladii), and weighted throwing arrows (plumbata) or shorter javelins (veruta) hidden in their shields. Colleagues of the heavy infantry were more mobile, and equipped with bows or shorter javelins worked, or even used battle axes and catapult artillery. Around 250 B.C. a slightly shorter javelin (spiculum) replaced the traditional pilum, but some researchers believe it was simply a new name for the same weapon – others indicate that among Germanic examples, the point was shortened.

The composition and organization of the army changed strongly, especially after the professionalization under Scipio around 200 BC, under Caesar and Augustus at the beginning of our era, and again strongly at the end of the Pax Romana around 150 AD .