Chester Nez, who has died aged 93, was the last survivor of 29 Navajo Americans who developed an unbreakable code that helped Allied forces win the second World War in the Pacific theatre.
He was one of a group recruited by the US Marine Corps to create a code based on their language that the Japanese could not crack.
About 400 code talkers would go on to use their unique battlefield cipher to encrypt messages sent from field telephones and radios throughout the Pacific theatre during the war. It was regarded as secure from Japanese military code breakers because the language was spoken only in the US southwest, was known by fewer than 30 non-Navajo people, and had no written form.
The Navajos' skill, speed and accuracy under fire in ferocious battles from the Marshall Islands to Iwo Jima are credited with saving thousands of US servicemen's lives and helping shorten the war. Their work was celebrated in the 2002 movie Windtalkers.
Nez was born in Chi Chil Tah, New Mexico into the Black Sheep clan. Relations between Navajos and the government at that time were largely hostile. As Nez recalled later, children were often taken from the reservations, placed in boarding schools and – ironically in the light of later events – forbidden to speak the Navajo language.
Last November, the American Veterans Center honoured Nez for bravery and valour above and beyond the call of duty, awarding him the Audie Murphy Award for distinguished service. "I was very proud to say that the Japanese did everything in their power to break that code but they never did," Nez told the Stars and Stripes newspaper the day before receiving the award.
Nez also served in the Korean War and retired in 1974 from a job as a painter at a Veterans Administration hospital in Albuquerque.