Throughout World War II, he served in the British Army in India as a member of the Queen's Royal Regiment.

As a junior officer at the age of 24, he received the Military Cross for gallantry during active operations against the enemy.

Following his army service, he began a business career and settled in 1961 on the island of Tresco in the Isles of Scilly, Cornwall, where he sketched and painted for relaxation.

He began by selling his work to tourists, who visited the Isles of Scilly in the English Channel, specializing at first in painting the local topography, seascapes, traditional ships, and boats.

On the completion of the Atlantic series, Hamilton started work on a new series of paintings on the War in the Pacific, widening his archival researches and interviewing to Canberra and Tokyo with extensive research work at the Naval Historical Center in Washington, D.C., With the help of foundations in Texas, Hamilton completed more than 120 paintings in five years.