He came to prominence after creating the Dothraki and Valyrian languages for the television series Game of Thrones.

[1][2] Studying at University of California, Berkeley (1999–2003), Peterson received BA degrees in English and in linguistics.

[6][7][8] He produced a number of videos on YouTube, in a series called The Art of Language Invention,[9] and published a book of the same title in 2015.

Peterson also worked as an executive producer on the 2017 documentary film, Conlanging: The Art of Crafting Tongues.

[10] In 2019, Peterson created a free High Valyrian course on the Duolingo website/app[11][12] and expanded the course in conjunction with the House of the Dragon series premiere in August 2022.