Turma

A turma (Latin for "swarm, squadron", plural "turmae"), (Greek: τούρμα) was a cavalry unit in the Roman army of the Republic and Empire. In the Byzantine Empire, it became applied to the larger, regiment-sized military-administrative divisions of a "thema". The word is often translated as "squadron" but so is the term "ala", a unit that was made up of several "turmae".
Roman army.
Republic.
In the 3rd and 2nd centuries BC, the time of the Punic Wars and Rome's expansion into Spain and Greece, the core of the Roman army was formed by citizens, augmented by contingents from Rome's allies ("socii"). The organization of the Roman legion of the period is described by the Greek historian Polybius (cf. the so-called "Polybian army"), who writes that each 4,200-strong infantry legion was accompanied by 300 citizen cavalry ("equites"). This contingent was divided into ten "turmae". According to Polybius, the squadron members would elect as their officers three "decuriones" ("leaders of 10 men"), of whom the first to be chosen would act as the squadron's commander and the other two as his deputies. As in earlier times, these men were drawn from among the 18 "centuriae" of the equestrian order, the wealthiest classes of the Roman people, who could afford to provide for the horse and its equipment themselves.
Empire.
With the reorganization of the army under Emperor Augustus (r. 27 BC – 14 AD) and his successors, the "turma" became the basic sub-unit of the cavalry, the rough equivalent of the infantry "centuria", both in the auxiliaries, who formed the bulk of the Roman cavalry, and in the legionary cavalry detachments. The auxiliary "cohors equitata" was a mixed unit combining infantry and cavalry, and existed in two types: the "cohors equitata quingenaria", with an infantry cohort of 480 men and 4 "turmae" of cavalry, and the reinforced "cohors equitata milliaria", with 800 infantry and 8 "turmae". Likewise, the purely cavalry "alae" contained either 16 ("ala quingenaria") or 24 "turmae" ("ala milliaria"). Individual "turmae" of camel-riders ("dromedarii") also appear among "cohortes equitatae" in the Middle East, and Emperor Trajan (r. 98–117) established the first all-camel cavalry unit, the "Ala I Ulpia dromedariorum Palmyrenorum".
The "turma" was still commanded by a "decurio", aided by two subaltern "principales" (under-officers), a "sesquiplicarius" (soldier with one-and-a-half times pay) and a "duplicarius" (soldier with double pay), as well as a "signifer" or "vexillarius" (a standard-bearer, cf. "vexillum"). These ranks corresponded respectively with the infantry's "tesserarius" (officer of the watch), "optio", and "signifer". The exact size of the "turma" under the Principate, however, is unclear: 30 men was the norm in the Republican army and apparently in the "cohortes equitatae", but not for the "alae". The "De Munitionibus Castrorum", for instance, records that a "cohors equitata milliaria" numbered exactly 240 troopers, i.e. 30 men per "turma", but also gives the number of horses for the "ala milliaria", composed of 24 "turmae", at 1000. If one subtracts the extra horses of the officers (two for a "decurio", one for each of the two subaltern under-officers), one is left with 832 horses, which does not divide evenly with 24. At the same time, Arrian explicitly says that the "ala quingenaria" counted 512 men, suggesting a size of 32 men for each "turma".
As for the legions, during the Principate, each had a cavalry contingent organized in four "turmae". A legionary "turma" was led by a centurion, assisted by an "optio" and a "vexillarius" as senior "principales". Each of them led a file of ten troopers, for a grand total of 132 horsemen in each legion. Their status was distinctly inferior to that of the legionary infantry: the centurions and "principales" of the legionary "turmae" were classed as "supernumerarii" and although their men were included in the legionary cohort lists, they camped separately from them.
In the late Roman army, the "turma" and its structure were retained, with changes in titulature only: the "turma" was still headed by a "decurio", who also led the first ten-strong file, while the other two files were led by subaltern "catafractarii", in essence the successors of the early Empire's "duplicarii" and "sesquiplicarii". Traces of this structure also apparently survived in the 6th-century East Roman army: in the late-6th-century "Strategikon of Maurice", the cavalry files are led by a "dekarchos" (, "leader of ten").
Byzantine Empire.
In the 7th century, as a result of the crisis caused by the early Muslim conquests, the Byzantine military and administrative system was reformed: the old late Roman division between military and civil administration was abandoned, and the remains of the East Roman army's field armies were settled in great districts, the "themata", that were named after them. The term "turma", in its Greek transcription "tourma" (τούρμα or ), reappears at that time as the major subdivision of a "thema". The army of each "thema" (except for the Optimatoi) was divided into two to four "tourmai", and each "tourma" further into a number of "moirai" (μοίραι) or "droungoi" (), which in turn were composed of several "banda" (singular: "bandon", βάνδον, from , "banner").
This division was carried through to the territorial administration of each "thema": "tourmai" and "banda" (but not the "moirai"/"droungoi") were identified with clearly defined districts which served as their garrison and recruitment areas. In his "Taktika", Emperor Leo VI the Wise () presents an idealized "thema" as consisting of three "tourmai", each divided into three "droungoi", etc. This picture, however, is misleading, as the sources do not support any degree of uniformity in size or number of subdivisions in the different "themata", nor indeed an exact correspondence of the territorial with the tactical divisions: depending on the tactical exigencies, smaller administrative "tourmai" could be joined on campaign and larger ones broken up. Since the elementary unit, the "bandon", could itself number between 200 and 400 men, the "tourma" too could reach up to 6000 men, although 2–5000 seems to have been the norm between the seventh and early tenth centuries.
Each "tourma" was usually headed by a tourmarchēs (τουρμάρχης, "commander of a "tourma""). In some cases, however, an "ek prosōpou", a temporary representative of the governing "stratēgos" of each "thema", could be appointed instead. The title first appears in circa 626, when a certain George was "tourmarchēs" of the Armeniac Theme. The "tourmarchēs" was usually based in a fortress town. Aside from his military responsibilities, he exercised fiscal and judicial duties in the area under his control. In the lists of offices ("taktika") and seals, "tourmarchai" usually hold the ranks of "spatharokandidatos", "spatharios" or "kandidatos". In function and rank, the "tourmarchēs" corresponded with the "topotērētēs" of the professional imperial "tagmata" regiments. The "tourmarchai" were paid according to the importance of their "thema": those of the more prestigious Anatolian themes received 216 gold "nomismata" annually, while those of the European themes received 144 "nomismata", the same amount paid to the "droungarioi" and the other senior officers of the "thema". In some sources, the earlier term "merarchēs" (μεράρχης, "commander of a "meros", division"), which occupied a similar hierarchical position in the 6th–7th centuries, is used interchangeably with "tourmarchēs". In the 9th–10th centuries, it is often found in the variant form "meriarchēs" (μεριάρχης). It has, however, also been suggested by scholars like J. B. Bury and John Haldon that the latter was a distinct post, held by the "tourmarchēs" attached to the governing "stratēgos" of each "thema" and residing at the thematic capital.
In the mid-10th century, the average size of most units fell. In the case of the "tourma", it dropped from 2–3000 men to 1000 men and less, in essence to the level of the earlier "droungos", although larger "tourmai" are still recorded. It is probably no coincidence that the term "droungos" disappears from use at around that time. Consequently, the "tourma" was divided directly into five to seven "banda", each of 50–100 cavalry or 200–400 infantry. The term "tourma" itself fell gradually into disuse in the 11th century, but survived at least until the end of the 12th century as an administrative term. "Tourmarchai" are still attested in the first half of the 11th century, but the title seems to have fallen out of use thereafter.