How Navajo Codes Helped the Allies Win World War II

Grammar Girl shares a compelling story about how Navajo codes helped the Allies during World War II, from new Unknown History podcast host and bestselling author Giles Milton.

Giles Milton, Writing for
2-minute read

Today, we have an excerpt from a fascinating book, When Hitler Took Cocaine and Lenin Lost His Brain.  The book is by Giles Milton, a renowned historian and bestselling author. He’s also the host of our new Quick and Dirty Tips podcast: Unknown History. In the show, Giles retells quirky, lesser-known stories from the past. 

I wanted to share one of Giles' stories about language. I love history—but I also love how history plays into our knowledge and perception of language, grammar, and storytelling.  Without further ado… I hope you enjoy this tidbit about codes that helped the Americans during World War II.

Let’s Talk Gibberish

The idea of using the Navajo language for battlefield communications was first suggested by Philip Johnston, the son of an American missionary. He was one of the few non-Navajos in the world who spoke the language fluently.


The commands were relayed as a string of seemingly unrelated Navajo words that bore no obvious relation to battlefield terms. This was because words like machine gun and battleship didn’t exist in Navajo.

To overcome this problem of vocabulary, the team used designated Navajo words to describe military hardware. Whale was used to describe a battleship, iron-fish to describe a submarine and hummingbird to describe a fighter plane.

But the code was a great deal more sophisticated than that. One of the basic principles was that specific Navajo words were chosen to represent individual letters of the Roman alphabet. To represent the letter A, for example, Tso could use any of the following: wollachee (ant), belasana (apple) or tsenill (axe). These words had one key element in common: when translated into English, they all started with the letter A.

The Americans sent and received dozens of commands each day. When they received a coded message, their first task was to translate the Navajo words into English. They would then use the first letter of each word to spell out the message. And this is why it proved so impossible for the Japanese to crack. Any code-breaker attempting to read the cipher had to know the meaning of the Navajo word in English. Since there was no Navajo dictionary, they found themselves up against an impossible task.


The Japanese code-breakers worked around the clock in their quest to crack the Navajo code, but never succeeded in deciphering a single message.

For more stories like this one, listen and subscribe to Unknown History with Giles Milton on iTunes, Stitcher, and Spotify.