An Ala (Latin for "wing", plural form: alae) was the term used during the mid- Roman Republic (338-88 BC) to denote a military formation composed of conscripts from the socii, Rome's Italian military allies. A normal consular army during this period consisted of 2 legions, composed of Roman citizens only, and 2 allied alae. Alae were somewhat larger than normal legions (ca. 5,400 v. ca. 4,500 men). From the time of the first Roman emperor, Augustus (ruled 30 BC - AD 14), the term ala was used in the professional imperial army to denote a much smaller (ca. 500), purely cavalry unit of the non-citizen auxilia corps, see Ala (Roman cavalry unit).