 One possible example is Britain, where one estimate puts the citizen pool in the 1st century at only 50,000 out of a total provincial population of around two million.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.