In this study, activities of the Ottoman State's Attaché militia Ömer Fevzi Bey during the First World War will be examined. During the First World War, Iran was of great importance both in the Entente States and in the Alliance States in terms of its geographical position. Germany and the Ottoman State wanted to spread through Iran to the Caucasus and Afghanistan. Thus, it was aimed to squeeze Russia in the Caucasus and disturb England in Afghanistan. There have been many initiatives on Iran to achieve that. Ömer Fevzi Bey was interested in the military ones of these initiatives. The communication with the headquarters of the agents, detachments and gangs sent to Iran was provided via Ömer Fevzi Bey. He spent intensive work in Iran for these initiatives to be successful. Besides, Ömer Fevzi Bey made suggestions to Istanbul by making plans about the region.

Keywords: Ömer Fevzi Bey, Iran, the Ottoman State, the Committee of Union and Progress, the First World War