Born into a working-class family in Warrington, Northern England, John Hansbury grew up in grinding poverty among the steel mills of Lancashire (now Cheshire). He had a gift for mathematics, and was able to take advantage of scholarships to get the education necessary to become a draftsman. As a youth he discovered the joys of the outdoors, and became a skilled mountaineer as a young man. As he worked in a protected occupation he could not be conscripted when WW2 started, so in late 1941 he volunteered with the RAF and became a navigator in Beaufighters over India, Burma, and Nepal. His mountaineering experience gave him the chance to lead fitness and survival training for RAF pilots in Kashmir, and earned him a British Empire Medal for his role in leading a party to safety following a treacherous storm in the Himalayas.
At the end of the war, eager to see more of the world before returning to England, Hansbury volunteered for a brief assignment in Hong Kong, and was tasked with surveying possible take-offs and approaches for a new airfield in the straight between Hong Kong and Kowloon. His resulting familiarity with the area and RAF experience led to him taking part in an air search for an RAF Dakota that had gone missing over Lantau Island in March 1946. Once the crash site was located, he led a party up the hillside to recover or bury any bodies that were located. His party elected to bury the casualties on the hillside, but they were later exhumed and re-buried in a Hong Kong cemetery.
Hansbury described a Hong Kong that was still reeling from the Japanese occupation, but determined to recover and rebuild. He returned home to England and his ever-patient wife in June 1946.