'Ala' (
Latin, wing ie wing of a bird or wing of an army), and its derivatives, 'Alares' and 'Alarii', were used in different or at least modified senses at different periods.
Early Republic
When a Roman army was composed of Roman
citizens exclusively during early Republican times, the flanks of the
infantry when drawn up in
battle array were covered on the
right and
left by the
cavalry; and hence ''Ala'' denoted the body of
horse which was attached to and served along with the foot-soldiers of the
legion (see Cincius, ''de Re Militari'', who, although he flourished in 200 B.C., is evidently explaining in the passage quoted by
Aulus Gellius, xvi.4
[1], the original acceptation of the term).
Mid-Republic
When, at a later date, the Roman armies were composed partly of Roman citizens and partly of
Socii (allies from the rest of the Italian mainland), either Latini or Italici, it became the practice to marshall the Roman troops in the centre of the battle line and the ''Socii'' upon the wings. Armies of the middle republic would consist of two legions of Roman citizens and two legions of "ala", with the ala supplying thirty turmae of cavalry per legion, whereas the Roman provided only ten turmae. Hence ''ala'' and ''alarii'' denoted the contingent furnished by the
allies, both horse and foot, and the two divisions were distinguished as ''dextera ala'' (right wing) and ''sinistra ala'' (left wing) (
Livy, xxvii.2
[2], Livy, xxx.21
[3], Livy xxxi.21
[4]; Lips. ''de Milit. Rom.'' ii. dial. 7. We find in Livy x.40
[5], the expression ''cum cohortibus alariis'' ("with wing cohorts"), and in x. 43
[6], ''D. Brutum Scaevam legatum cum legione prima et decem cohortibus alariis equitatuque ire...jussit'' ("He ordered Decius Brutus Scaeva, legate, with the first legion and ten wing cavalry cohorts, to go and oppose said detachment...").
Late Republic
When the whole of the inhabitants of
Italy had been admitted to the privileges of Roman citizenship the terms ''alarii'' and ''cohortes alariae'' were transferred to the foreign troops serving along with the Roman armies. In
Julius Caesar (''The Gallic War'' i.51
[7]) we see the ''Alarii'' expressly distinguished from the ''legionarii'', and we find the phrase ''cohortes alariae et legionariae'' (''The Civil War'' i.73
[8]), while
Cicero (''ad Fam.'' ii.17
[9]) speaks of the ''Alarii Transpadani''.
Empire
Lastly, under the
empire, the term ''ala'' was applied to
auxiliary cavalry regiments, raised it would seem with very few exceptions in the provinces, operating as fighting cavalry independent of the legions and the non-combatant legionary cavalry.
Sources
''This article is based on an article by William Ramsay, M.A., Professor of Humanity in the University of Glasgow on pp 73-74 of "A Dictionary of Greek and Roman Antiquities", John Murray, London, 1875, edited by William Smith, D.C.L., LL.D. This article is in the
public domain. The information contained herein, as such, may therefore be outdated.''
References
★
Ann Hyland: ''Equus: The Horse in the Roman World'', ISBN 0-300-04770-3
★ Adrian Goldsworthy: ''The Complete Roman Army'', ISBN 0-500-05124-0
★ William Smith, ed.: ''A Dictionary of Greek and Roman Antiquities'', John Murray, London, 1875