The early 1880s saw a rapid increase in the size of the colonial military forces. Between 1883 and 1885, the force rose from 8,000 to 22,000 men, although only roughly 1,000 of these were permanent soldiers. In 1885, unpaid volunteer soldiering returned following the dispatch of a contingent of New South Wales soldiers to fight in the Sudan led to fears of a Russian attack on Australia. The resultant wave of patriotism forced the colonial governments to allow citizens to form new units of "second-line" troops who were not as well trained as the paid volunteers or voluntary militiamen. This wave of patriotism resulted in the development of the concept of mounted infantry soldiers within Australian forces, which would later be used in the Boer War and in the First World War as the "light horse", and it was around this time that an Australian character arguably began to develop amongst the colonial forces.