The legions, which had been a mix of life professionals and civilian campaigners, was altered into a standing army of professionals only. The actual structure of the cohort army remained much the same as in the late Republic, although around the 1st century AD the first cohort of each legion was increased in size to a total of 800 soldiers. However, while the structure of the legions remained much the same, their make-up gradually changed. Whereas early Republican legions had been raised by a draft from eligible Roman citizens, imperial legions were recruited solely on a voluntary basis and from a much wider base of manpower. Likewise, whereas Republican legions had been recruited almost exclusively in Italy, early Imperial legions drew most of their recruits from Roman colonies in the provinces from 68 AD onwards. One estimate places the proportion of Italian troops at 65% under Augustus in c. 1 AD, falling to around 49% by the end of Nero's reign.