Öz
In the history of diplomacy, which lasted for centuries from the foundation of the Ottoman Empire to its collapse, the tradition of writing sefaretname (the book of embassy) about the activities of the ambassadors was maintained by many ambassadors. Among the ones written during the Ottoman period, most of the sefāretnāmes that have survived to the present day were written by temporary ambassadors or their entourage. There were also sefāretnāmes scribed by permanent ambassadors. The work named "Haydar Efendi's Sefāretnāme in Iran", which is the subject of the study, was the first sefāretnāme written after the permanent embassy was opened in Iran. This sefāretnāme written by Haydar Efendi who took part in the delegation of Ahmet Vefik Efendi, when appointed as ambassador to Tahran on June 15, 1851, as the embassy undersecretary. In this sefaretname, the journey of the delegation of Ottoman embassy and how the Iranian side welcomed the Ottoman embassy are explained in detail. In addition, the sefaretname contains detailed information about the attitudes and behaviours of both the Ottoman delegation and the ambassador in connection with the welcoming ceremonies by the Iranian side.