John Worsley joined the Royal Navy in 1939. His depictions of life on board ship were soon acquired by the War Artists Advisory Committee (WAAC). In July 1943, the WAAC appointed him as an official war artist to the Admiralty. This meant an annual salary of £650, art supplies, and the assurance that his work would be exhibited. He was assigned to the staff of the commander-in-chief in the Mediterranean to record action there. The Melilli caves (about 20 km north of Syracuse) were an awe-inspiring spectacle. A natural cavern, the site had been further excavated by the Italians for use as engineering workshops and to store munitions
Later that year, Worsley was captured in the Mediterranean and spent the rest of the war in a naval officer's prison camp, Marlag ‘O’ at Westertimke, near Bremen in north Germany.