The Union of South Africa Defence Force was established when the South African Defence Act, No 13 of 1912, was published in November that year and included the Active Citizen Force (A.C.F.) [Afr: Aktiewe Burgermag (A.B.M.)], consisting of three batteries of field artillery, nine regiments of mounted riflemen - to be increased to 11 regiments and six independent squadrons - three brigades each of four battalions of infantry, an aviation corps, four mounted and three dismounted and three infantry brigade trains, two mounted brigade field ambulances - to be increased to seven - and two field ambulances.