How were cavalry units configured in the Roman legions?

Answer 1

The Role of the Roman cavalry was to flank the infantry

In the mid and late republic, a Roman army was composed of two Roman legions of 4200 infantry and to alae (troop supplied by Rome's Italian allies). The cavalry flanked the infantry and was composed of 10 Roman tumae (wings) of 30 horses each, which gave 300 horsemen, and thirty allied turmae which gave 900 horsemen. The turma was commanded by a decurio, aided by two subaltern principales (under-officers): a sesquiplicarius (soldier with one-and-a-half times pay), a duplicarius (soldier with double pay) and a vexillarius (a standard-bearer). Each of these officers led a file of 10 horses.

In the early period of rule by emperors a Roman legions had 4 turmae, which gave a cavalry of 120. Including the decurio, the sesquiplicarius and the duplicarius, the total was132. The bulk of the cavalry was provided by auxiliary troops of the non-Romans of the empire. There were two types of auxiliary cohort equitas (cavalry cohort): the cohors equitata quingenaria, which had 480 infantry and 4 turmae, and the reinforced cohors equitata milliaria, which 800 infantry and 8 turmae. The purely cavalry alae (auxiliary units) were the ala quingenaria, which had 16 turmae and the ala milliaria, which had 24 turmae. A document recorded that the cohors equitata milliaria had 240 horses (that is, 30 men per turma), and the ala militaria had 1000 horses, which does not divide evenly into 24 tumae and gives much more than 30 horses per turma. Another source records 512 horses for the ala quingenaria, which gives 32 horses per turma.

In 212 the emperor Caracalla extended Roman citizenship to all free males in the empire and technically, a citizen cavalry was used. Around 258 the emperor Gallienus introduced rapid deployment cavalry units for the defence of the frontiers of the empire. The cataphract, a form of armoured heavy cavalry, appeared in the 4th century.

Answer 2

The "legion system" developed by ancient Rome was revised several times during the history of Rome. So too was their cavalry attachments. Here are some relevant facts concerning the Imperial legions. Imperial meaning post - Republic era. In some cases the cavalry:

1. Was part of each legion and consisted of a unit of 128 mounted soldiers; they were best used as reconnaissance forces and messengers.

2. As auxiliaries, and not every legion had the luxury of auxiliaries;

3. The decuria, this was the smallest unit and had at times either 8 or 10 men;

4. The ala, was a large unit and ala referred to their position on the wings of a legion's battle line. This, most importantly helped against flank attacks;

5. In the best of times the so-called ala quingenaria of 512 men in sixteen troops of 32 men;

6. In late years, the ala quingenaria totaled 768 troops and officers;

7. Different configurations were created as horsemen were available. The Jewish historian, and Roman citizen has supplied more detailed information on cavalry, especially in time around 4 BC.

Cavalry in ancient times was not as useful as in later years when the stirrup was invented which gave the rider more leverage and more power. Also, Roman cavalry horses did not have "horse shoes". However, the Roman military was essential to the power of the legions in any campaign. With that said there were trained cavalry specialists. The Roman cavalry evolved over time and had variants. Remembering that Rome had ongoing military operations at all times, more structure was added. However, unsaddled Numidian cavalry rode bare back, and non- Numidians used a saddle.

In Roman times, cavalry without the heavy legionaries, were not a major threat to an opposing army. However, war history records at times that stirrup cavalry units were powerful forces all on their own. This disappeared, however, by the time of the US Civil War.

Not to ever be caught off guard, the Romans did not neglect their cavalry units and they evolved with time, and there was plenty of time and plenty of wars to do this.

Some emperors actually wrote "military procedures" for cavalry exercises, and they had manuals for performing maneuvers in times of peace. By the 4th century, cavalry units continued to evolve.