During the early years of the 1880s , an Egyptian regime in the Sudan , backed by the British , came under threat from rebellion under the leadership of native Muhammad Ahmad ( or Ahmed ) , known as Mahdi to his followers . In 1883 , as part of the Mahdist War , the Egyptians sent an army to deal with the revolt , but they were defeated and faced a difficult campaign of extracting their forces . The British instructed the Egyptians to abandon the Sudan , and sent General Charles Gordon to co @-@ ordinate the evacuation , but he was killed in January 1885 . When news of his death arrived in New South Wales in February 1885 , the government offered to send forces and meet the contingent 's expenses . The New South Wales Contingent consisted of an infantry battalion of 522 men and 24 officers , and an artillery battery of 212 men and sailed from Sydney on 3 March 1885 .