https://wikiofthrones.com/game....-of-thrones-dothraki

Game of Thrones' Dothraki creator reveals he "rarely worked with actors" - Wiki of Thrones
wikiofthrones.com

Game of Thrones' Dothraki creator reveals he "rarely worked with actors" - Wiki of Thrones

David J. Peterson developed the Dothraki and High Valyrian languages specifically for the TV adaptation of Game of Thrones.