The Navajo code talkers were Navajo servicemen who used their native language as code during WWII. Philip Johnston, who spoke Navajo fluently, proposed the idea since very few others spoke the unwritten language. In 1942, 29 Navajos attended boot camp to develop a code based on their language. They transmitted hundreds of messages during key battles like Iwo Jima. The Japanese were never able to break the Navajo code, though they deciphered other Allied codes. Over 500 Navajos served as code talkers during WWII, helping secure Allied victories.