The Roman Army

Ala

An ala was a cavalry detachment consisting of 500 to 1000 riders. In order to become a member of an ala, one needed to belong to the Roman equestrian class called »ordo equester«. Anyone who was in the possession of 400 000 sesterces and whose ancestors had been born as free men for at least three generations, could be admitted to the equestrian class. It was the Emperor who decided about the affiliation. He often ignored the above-mentioned criteria generously. One estimates that there were approximately 20 000 equestrians at the time of the Emperor Augustus.

If a member of the Roman equestrian class was admitted to an ala, he received a state-owned horse and henceforth he was an »eques equo public«, i.e. »rider with a public horse«.  There also existed an inofficial, »second degree« equestrian class. The members served with their own horse (»equus privatus“) and did not fulfil all the requirements. For example, they could not obtain a reserved seat in the first two rows of the theatres in Rome because these were exclusively reserved for the »true« equestrians.

At the time of Caesar’s reign, the existing Germanic cavalry detachments of allied Germanic tribes had been recruited, but were not directly part of the Roman Army. This changed after Augustus’ military reform: Consequently, the Germanic units were an integral part of the regular army. An ala was tightly organised. It was led by a prefect (»praefectus«) who often was a former centurion in a legion. The alas consisting of members of allied tribes were often commanded by their own leader, as was the case with Arminius and the Cherusci. A Romanisation of these troops – gradually taking place due to the service in the Roman Army - was definitely intended.

The standard of the cavalry was the »vexillum«. It was composed of a lance and a crossbar attached to the top of this lance. The rectangular bunting was hanging down from this crossbar. Bands with metal hangers in the shape of ivy leaves would hang down on the left and right side of the bunting. Due to its mostly red colour, it was also called »flame« (»flamma«). Sometimes, the head of the lance was additionally ornamented and inscriptions or symbols were drawn onto the bunting.  
 
The  bridle of the horses was decorated with embellishments made of iron or bronze, partially silvered or tinned. In connection with the Roman cavalry, so-called hoof boots are often mentioned. Their use however could not yet be proven beyond doubt. The Romans did not use stirrups. Instead, they would sit firmly due to a saddle fitted with »horns" at each corner. The equestrian wore a short garment  named »trabea«. In Augustan times, this could also be the slightly longer »toga praetexta« which was worn over a short tunica. The long woollen scarf called »focale« would warm up the neck. The most common coat in the first century AD was the »paenula«. This was a kind of poncho with a hood. It was made of felted cloth which was water-repellent and warm. They would also wear »tibilia« to keep their legs warm. These were wraparound socks - similar to spats - made of cloth or fur. The equestrians had soft leather boots which covered the foot and ankle. These were not fastened with laces and the edges were folded. The non-Roman riders often wore tight fitting, knee-length breeches. They were made of soft leather or cloth and the Romans called them »feminalia«. With regards to the clothing regulations, ancient illustrations show that the exception seemed to be the rule.

The equestrian soldiers in the ala units were primarily  armed with light throwing spears called »iacula« or »lancea«. They were either carried in the hand which held the shield or they were transported in a spear quiver. The momentum and the range of the throw were enhanced by loops which were situated just behind the mass centre of the weapons and which increased the spin. The range of the throws could easily be over 70 metres (79.5 yards).

The side weapon used in the cavalry was a short sword named »spatha«. It was mainly used as a baton and was carried in a sword scabbard tied to a belt. As opposed to the military belt in the legions, the belt in the cavalry was plain and not ornamented. However, a unit of »sagittarii« (bowmen) from Upper Germania was, in addition to the cavalry sword, equipped with bow and arrow. This armament was rather unusual for the cavalry in Augustan times, but subsequently it became more common. For defence purposes they had a round shield made of leather or wood. A flexible chain mail and an iron or bronze helmet completed the equipment. Equestrians in ala units occasionally had helmets with face masks. The use of these is still controversial.  M. Junkelmann assumes that the whole equipment of an equestrian soldier in the first century AD weighed between 22 and 30 kg, depending on the additional parts like arm guards and shin guards. 

By the way: 12 of the 23 known praetorian prefects in the first century AD, who had to be members of the equestrian class to be able to hold this office, participated in conspiracies and coup attempts.