At the same time as the legions underwent these transformations, the "auxilia" were reorganized and a number of allied troops were formalised into standing units similar to legions. Rather than being raised re-actively when required, the process of raising auxiliary troops was carried out in advance of conflicts according to annual targets. Whereas the internal organisation of the "auxilia" had previously been left up to their commanders, in the early empire they were organised into standardised units known as "turmae" (for cavalry "alae") and "centuriae" (for infantry "cohortes"). Although never becoming as standardised in their equipment as the legions, and often retaining some national flavour, the size of the units at least was standardised to some degree. Cavalry were formed into either an "ala quingenaria" of 512 horsemen, or an "ala millaria" of 1,000 horsemen. Likewise, infantry auxilia could be formed into a "cohors quingenaria" of 500 men or a "cohors millaria" of 1,000 men. Mixed cavalry/infantry auxiliaries were typically formed with a larger proportion of foot than horse troops: the "cohors equitata quingenaria" consisted of 380 foot and 120 horsemen, and the "cohors equitata millaria" consisted of 760 foot and 240 horsemen.