Qajar dynasty is a period full of ups and downs in the history of Persian language and literature. This is due to many factors, the most important of which is the considerable change in written Persian because of political, scientific, cultural, military, etc., relations with the West. Foundation of Darolfonoon, the great translation movement, development of travelogues, popularity of newspapers, improvement of people's knowledge, the advent of Mashrooteh revolution, etc., have all played a role in bringing a change to Persian (including its words, prose, etc.).Concerning military terms, among European languages, Persian has been mostly affected by French in this period, with English and Russian ranking next; however, when it comes to Eastern languages, Arabic and Turkish, sharing historical, political, cultural, and religious origins with Persian, are the ones that affected Persian military terms the most. In the late Qajar period, a number of military officers realized that a myriad of foreign military terms had entered Persian, and so they decided to compensate for this deficit from 1922 on. In the end, this sense of commitment to protect the status of Persian led to the foundation of Farhangestan-e Iran.