Watkins completed the Hawkesbury Diploma of Agiculture Course (HDA) in 1913. Caption at bottom of photograph 'Lieutenant HT Watkins, C Company, 13th Battalion, 4th Brigade Infantry AIEF'.
Watkins was killed at the Dardanelles, April 1915 (see HAC Journal 1915, Vol.12 p.17 and p.83) in World War I (WWI). The AIEF was the Australian Imperial Expeditionary Force.