From 1870 until 1901 , each of the six colonial governments was responsible for their own defence . The colonies had gained responsible government between 1855 and 1890 , and while the Colonial Office in London retained control of some affairs , the Governor of the each colony was required to raise their own colonial militia . To do this , they were granted the authority from the British crown to raise military and naval forces . Initially these were militias in support of British regulars , but when military support for the colonies ended in 1870 , the colonies assumed their own defence responsibilities . The colonial military forces included unpaid volunteer militia , paid citizen soldiers , and a small permanent component . They were mainly infantry , cavalry and mounted infantry , and were neither housed in barracks nor subject to full military discipline . Even after significant reforms in the 1870s — including the expansion of the permanent forces to include engineer and artillery units — they remained too small and unbalanced to be considered armies in the modern sense . By 1885 , the forces numbered 21 @,@ 000 men . Although they could not be compelled to serve overseas many volunteers subsequently did see action in a number conflicts of the British Empire during the 19th century , with the colonies raising contingents to serve in Sudan , South Africa and China .