Domen
Misico dux Vandalorum
Any idea on the proportions of archers to spears to various cavalry units in ancient armies?
As Flying Pig wrote, number of cavalry in Roman Republican armies was relatively small. But during Imperial times number, quality and importance of cavalry increased. By the later 4th century AD, cavalry was about 1/3 (around 36% - 38%)* of the Roman army, including around 50% of the limitanei and riparienses (border defence troops) and around 20% of the comitatenses and palatini (field troops). In Emperor's personal guard, cavalry was majority (bodyguard divided into scholae palatinae, candidati and domestici - of which scholae palatinae and candidati were entirely cavalry, while domestici were both infantry and cavalry).
*According to another source not 1/3, but "only" around 25%.
In Late Roman army, heavy lancers played an important role. There were 3 types of them (similar in equipment, they had different roles in battles):
- cataphracti (used to fight mostly against enemy infantry)
- clibanarii (used to fight mostly against enemy cavalry)
- cataphractarii (unclear; they could be just another name for cataphracti)
Differences in equipment were relatively minor (cataphracti had more complete armour than clibanarii; clibanarii used shields, while cataphracti usually not). Main offensive weapons were similar - long spear (we can call it lance, though it was not like Medieval long lance), sword. Sometimes other weapons.
When it comes to roles in battles - they weren't strictly observed; in fact often clibanarii were used as cataphracti, or cataphracti as clibanarii.
When attacking cavalry they usually used wedge formation, with clibanarii in front and armoured horse archers behind them. When attacking infantry they usually used line formation, or several lines. Cataphracti in front.
Above mentioned types of heavy lancers were supported by armoured horse archers, usually called sagittarii clibanarii (clibanarii archers).
The role of heavy horse archers was to provide close fire support for lancers and to cooperate with them. They advanced behind lancers.
Light cavalry had various names, depending on where it was recruited from (for example equites dalmatae, equites mauri, etc.).
Light cavalry usually had short mail armour, javelins for throwing, spear and sword for fighting in melee and a shield.
Then there were units of light horse archers (equites sagittarii) - who were not as well armoured as sagittarii clibanarii.
There was also "special formation" of cavalry, called dromedarii - they were using camels instead of horses. The only known unit of dromedarii was ala I Ulpia dromedariorum Palmyrenorum (created by Emperor Trajan), but probably there were also some sub-units of camel riders in other auxiliary units.
Cavalry in Late Roman armies was better paid than infantry, and was considered elite of the army. Cavalry training was more intensive and longer than infantry training. Also requirements to become a cavalry soldier were higher - people who could be recruited to Late Roman cavalry were:
- distinguished, experienced soldiers of infantry
- sons of veterans of cavalry, with their own horses
- people with high social status
- barbarians from tribes famous for skilled horsemen
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Late Roman infantry was even more diversified than cavalry in types and equipment used.
But definitely spear and bow increased their importance compared to Republican times.
Also swords became longer, and more frequently used for cutting than stabbing.
Infantry formations became tighter and more defensive / less offensive in nature compared to Caesar's times.
But there appeared also many "specialist", good quality units of auxiliary light infantry, recruited from various barbarian tribes. Those light infantrymen fought with their own traditional weapons, so you can imagine that diversity.
Importance and number of ballistas, catapults and other artillery also increased.
By the later 4th century AD, cavalry was about 1/3 (around 36% - 38%)* of the Roman army
*According to another source not 1/3, but "only" around 25%.
By comparison proportion of cavalry in several battles of 3rd and 2nd centuries BC (numbers for both opposing sides combined):
Sellasia 222 BC - ca. 1/26 was cavalry
Cannae 216 BC - ca. 1/7 was cavalry (and Carthage had cavalry advantage)
Zama 202 BC - ca. 1/8 was cavalry (and Rome had cavalry advantage)
Cynoscephalae 197 BC - ca. 2/19 was cavalry
Pydna 168 BC - ca. 2/17 was cavalry