This article reconsiders the accepted views on the annexation and ‘provincialisation’ of Galatia by expanding on the military-related factors involved. It is argued that the annexation helped provide Rome with the necessary resources, including manpower, to maintain Augustus’ ‘New Model’ Army as established between 30 and 25 BC, as well as providing land for the future discharge of legionary veterans. The achievements of the known governors of Galatia for 25 BC-AD 14 are reviewed also, noting how their senatorial status as pro-praetor or pro-consul had no bearing on the type of garrison they commanded. The process of establishing the Augustan coloniae ‘in Pisidia’ is then re-examined, as is the evidence for the character of Ancyra, Pessinus, and Tavium in the pre- and immediate post-annexation period. The data for the garrison of Augustan Galatia is then surveyed, concluding that the legiones V and VII took part in the annexation and probably remained there until AD 8, these legions being supported by auxiliary units that remained in the province after their departure. Finally, the evidence for the formation of the legio XXII Deiotariana is re-assessed, concluding it was indeed constituted under Augustus using the former Galatian Royal Army.