Nathan enlisted on 22nd January 1901. He was 20 years and 8 months old, and was a photo etcher by trade. He was active service in South Africa from 1901 to 1902, then having completed his service period on 22nd January 1913 was transferred to Army Reserve. He was mobilised on the outbreak of war, entering the war in France on the 18th August 1914. He was awarded the Distinguished Conduct Medal "For gallantry on 22nd October, in leading a party of stretcher bearers in daylight, under heavy rifle fire for a quarter of a mile, to bring back a wounded serjeant." On 12th December 1914 he gained promotion to the rank of Corporal. In 1916 and 1918 he served under the rank of acting Serjeant with pay.