Navajo was the traditional language of the Navajo Code Talkers who served in the U.S. military during World War II.
The U.S. Marine Corps recruited Navajo speakers to develop and operate a voice communications code. Their work began in 1942, and the code used Navajo words and specially created terms for military concepts. Navajo’s complex grammar and relatively limited number of non-Navajo speakers made it difficult for Japanese codebreakers to interpret.
The Code Talkers transmitted messages during major Pacific campaigns, including Guadalcanal, Iwo Jima, and Okinawa. Their communications helped units coordinate operations while reducing the risk that radio traffic would reveal military plans.
Navajo is also called Diné Bizaad and belongs to the Athabaskan branch of the Na-Dené language family. The Code Talkers did not simply speak ordinary Navajo and assume it was automatically a code; the military program added a structured vocabulary and encryption procedures. Other Indigenous speakers also served as code talkers, but the Navajo program became the best-known.