Early in the Roman Republic, the Cavalry were formed by the Romans themselves.
Between the Second Punic War (218-201 BCE), and the Marian Reforms (107-101 BCE), the Cavalry were recruited from other nations.

Legionary Cavalry

At the Battle of Cannae, according to Polibius, the 6,000 Roman Cavalry were outnumbered by 10,000 Celtic and Numidian Cavalry.
During the Battle, the 6,000 Roman Cavalry were reduced to 370. After this, the Romans hired the Numidian Cavalry where they won at the Battle of Zama (202 BCE).

After the Battle of Cannae, the Romans always kept a Regiment of Numidian Cavalry in the Roman Army.
Under the Roman Republic the Cavalry were always recruited from the Citizens of Rome.
After the Marian Reforms, the Cavalry were recruited from other nations, and by the time of the Roman Empire, the Cavalry were almost entirely supplied by the Roman Auxiliaries.

Under the Principate, each Legion had a Cavalry detachment of 120-132 Horse in four Turmae.
Each Legion would also have additional Auxiliary Regiments of Cavalry attached to it.
The Officer in charge was a Decurion, his two senior officers (Principales) were an Optio and a Vexillarius.
The Alaris, cavalry soldier, earned 20% higher salary than the Auxiliary or Legionary foot soldier.

Spatha
- was a 3 ft (90cm) sword which was longer than an Infantryman’s sword, in order to reach down to the Infantry. It fitted into a Scabbard made of leather or wood.
Spears
- He carried three throwing spears, hung in a quiver on the horse’s flank.
Shield
- A circular or hexagonal shield made of layers of wood covered in hide and reinforced with a steel boss.
Helmet
- He wore a metal Coolus Helmet, similar to the Infantry helmet, but with flaps protecting the back and sides of the head.
Armour
- He wore mail or scale armour, and some wore breastplates.
Roman Saddle
- Roman Cavalry did not use the stirrup, this was introduced after the Decline and Fall of the Roman Empire (476 CE).
- Instead, the Roman Saddle had four corner posts to hold the rider in position.
Roman Horseshoe
- The Hipposandal or Roman Horseshoe did not use nails until after the fifth Century CE. Instead the lead or iron shoe was wrapped around the hoof.

The preferred horses were bred from stock which came from Persia, Cappadocia, Iberia and Libya.
According to Polybius, horses were fed on Barley and were allocated 6 Bushels per month.

Numidian Cavalry were employed during the Second Punic War (218-202 BCE).
Dalmatian Cavalry Units were famous and referred to in the Notitia Dignitatum (c.395 CE).
Sarmatian Allied Cavalry Units were located in Britannia by Marcus Aurelius (161-180 CE).

Vegetius (4th century CE) wrote Digesta Artis Mulomedicinae’, a lesser known Work than his ‘De Rei Militari’, which is a treatise on Veterinary Medicine.
In Book III, the first four chapters deal with the Anatomy of Horses.

After 106 CE each Legion had 6 Dracoanrii who carried the Draco. Draco meant dragon or serpent.
The Draco was the military standard of every Roman Cavalry Cohort, according to Vegetius, which was carried by the Draconarius.
The Draco was the equivalent of the Standard of the Legion, which was an eagle, the Aquila.
Arrian described it as being Scythian, and that it inflated and whistled when the horse was running.

Signals were transmitted by the Standard Bearer using a Bugle.
Calls were given to the Cavalry to Charge, Retreat, Assemble, Disperse, Mount and Dismount, and so on.

The Cavalry were deployed on the flanks of the Legion in Battle to protect and screen the Infantry from the enemy Cavalry.
They were organised in their Turmae and arranged in three ranks.
Within the Turma they often rode in echelon, each rider’s shield protecting the next one.
Cavalry were also used in Scouting, Skirmishing and Pursuit of a vanquished enemy.

Auxiliary Cavalry

This was a Regiment of Roman Auxiliaries commanded by a Roman Officer, the Prefect.
An Ala, meaning ‘Wing’, would consist of 480 men, made up of 15 or so smaller ‘Turmae’ or ‘Squadrons’.
Each Turma or ‘Squadron’ consisted of 30 or 32 men.
Each Squadron dived into 3 ‘Decuriae’ or ‘Troops’ of 10 men each.
Each Turma or ‘Squadron’ had a Commanding officer called the Decurion, and two officers (Principales), a Sesquiplicarius (one and a half times pay) , and a Duplicarius (double times pay), and a Signifer (Standard Bearer).
The Cavalryman was known as the Eques or Eques Alaris (Auxiliary Cavalryman).
Other Titles include the Centurio Exercitator (Cavalry Training officer), Eques Speculator (Mounted Scout), Eques Stablesianus (Cavalry stablehand) and Eques Sapsarius (Mounted medic).

Also known as Clibanarii meaning ‘Oven Men’ due to overheating inside their armour.
Under the Late Roman Empire Squadrons of heavy Cavalry were employed called Cataphract
These were the ‘Tanks’ of Ancient Rome and a head on charge would crush everything before them.
Both the rider and horse wore metal armour.
The first unit appeared under Hadrian (117-138 CE), the Ala I Gallorum et Pannoniorum Catafractata.

There were three types of Auxiliary Regiment consisting of 500 men (Quingenaria) and three types consisting of 1000 men (Milliaria).
By 23 CE, Tacitus states that there were as many Auxiliaries as there were Legionaries. He says that there were 250 Auxiliary Regiments consisting of:
50 Alae (‘Wings’ of Cavalry only), 120 Cohortes (Infantry), and 80 Cohortes Equitatae (Mixed Infantry with Cavalry).

Ala Quingenaria (Wing)
- All Cavalry Regiment with 480 Horse: 16 Turmae of 30 or 32 Horse in each.
  The commander of a Turmae was the Decurion.
Cohors Quingenaria (Cohort)
- All Infantry Regiment with 480 Foot Soldiers: 6 Centuriae of 80 men each.
Cohors Equitata Quingenaria
- Mixed Cavalry and Infantry Regiment with 480 Infantry and 120 Horse. Total 600 men. 6 Centuriae of 80 men each and 4 Turmae of 30 or 32 Horse.

Ala Milliaria
- had 720 or 768 men: 24 Turmae of 30 or 32 Horse each.
Cohors Milliaria
- had 800 men: 10 Centauriae of 80 men each.
Cohors Equitata Milliaria
- had 1040 men: 800 infantry and 240 Horse: 10 Centuriae of 80 men each and 8 Turmae of 30 or 32 Horse.

In c.117 CE, Trajan created the Ala I Ulpia Dromedariorum Milliaria based in Syria.
‘Dromedarii’ meant they were camel mounted troops of the Auxilia.
‘Milliaria’ usually meant an ‘Ala Milliaria’ of 720 or 768 Riders, consisting of 24 Turmae of 30 Horses each, in this case, Camels.

In 260 CE, the Roman Emperor Gallienus created a Cavalry Regiment, the Comitatenses, separate from the Legions and able to move to any Frontier or Region at short notice.
They were based in Milan, and able to move in a few days to stop a Germanic incursion or suppress a Rebellion.
The Comitatenses were still listed as existing in the Notitia Dignitatum (c. 400 CE).

In c.30 BCE, Augustus created the Imperial Horse Guard which was a Regiment of Cavalry recruited almost entirely from the Batavi Germanic Tribe.
They numbered 500 initially under Augustus, gradually increasing to 2,000 before being disbanded by Constantine I in 312 CE.
They were completely loyal to the Roman Emperor and guaranteed his personal safety.
Their Role was to carry out Ceremonial Duties, State events and Daily Palace guard duties. They were also used by the Emperor as messengers to carry secret intelligence signals and used as undercover agents.