Allan James Shackleton was born on 21 March 1897 in Waimate, a small provincial town in South Canterbury, New Zealand.

Shortly after his 20th birthday, he enlisted as a soldier in the New Zealand Expeditionary Force, and then endured the horrors of World War I (1914-1918). For 24 months he fought in the battles of the Somme, Mons, Gommecourt Wood and the Hindenburg Line. He was one of only two in his original unit of several hundred men to survive. His survival and several narrow escapes from death, strengthened his religious faith and convinced him of the futility of war.

Following the war, he attended Canterbury University, Christchurch, New Zealand, and graduated with the degree of Bachelor of Engineering (Electrical). He was awarded a postgraduate apprenticeship at Metropolitan Vickers, which at that time was a large and thriving heavy electrical engineering company in Manchester, England.

A few years later, the prospect of unemployment at Metropolitan Vickers during the Great Depression of the early 1930s compelled him to return with his family to New Zealand in search of better employment opportunities. Shortly before the Second World War, he was appointed head of the engineering department at the local high school in Gisborne. During the Second World War, he was unwillingly conscripted into the local "Home Guard" but, owing to his age, was ineligible for a further period of active duty overseas.

In 1946, he successfully applied for the position of Industrial Rehabilitation Officer with the United Nations Relief and Rehabilitation Administration (China Mission). Initially, he worked in Shanghai but at the onset of the communist uprising in China was posted to Formosa (Taiwan).

After his arrival in Taiwan, the Formosans rebelled against Generalissimo Chiang Kai-Shek’s military regime. On 28 February 1947, he again found himself in a war zone. During December, 1947, at the end of his term of duty he left Taiwan to return to his family in Gisborne.

He retired from a career of teaching at the age of 70. In his later years he spent much time writing "The Passing Years", an incomplete autobiography which describes his experiences during the First World War in some detail.

He died in New Plymouth, New Zealand, at the age of 87 and is survived by his wife and two sons.