Corresponding member of Azerbaijan National Academy of Sciences Ogtay Abdul oglu Efendiyev was born on March 26, 1926 in Baku. In 1945 he entered the Faculty of Oriental Studies of the Azerbaijan State University (present BSU), and in 1946-1950 he continued his education at the Iranian branch of the Moscow Institute of Oriental Studies. He returned to Baku in 1950 and graduated from the Institute of Oriental Studies of the USSR Academy of Sciences in 1951 and in 1955 he defended his dissertation in Moscow and received the name of PhD. He returned to Baku in that year and began to work in the Department of Ancient and Medieval History of the History Institute. In 1957-1958, in 1970-1972, he was entrusted with the position of the head of that department. In 1975, he was elected head of the medieval history department of Azerbaijan. O. Efendiyev has been awarded the title of Doctor of Historical Sciences in 1969, professor of science in 1993, and in 2001 he was elected as a corresponding member of ANAS.
The main direction of O. Efendiyev's scientific work is related to the study of the history of statehood in medieval Azerbaijan. He has scientifically justified the exceptional and leading role of our people in the development of the Safavid (Goldenbish) state founded by Shah Ismail for the first time and proved that this state is the Azerbaijani state. He published Fazlullah Ruzbihan's "Tarihi-alam-arayi amini" (Baku, 1987) and the Azerbaijani traveler and diplomat “Oruj bay Bayat - Iranian Don Juan's book” (Baku, 1988) for the first time.
O. Efendiyev is the author of 150 scientific articles, reviews and collective works (including 30 abroad). He was a member of the editorial board of the Academic publication of the "History of Azerbaijan" (7 volumes), and is the main editor and co-author of the third volume covering XIII-XVIII centuries.
O. Efendiyev has repeatedly been a participant and reporter of international scientific conferences and meetings (Moscow, St. Petersburg, Almaty, Tashkent, London, Medison, Istanbul, Ankara, Kayseri, etc.).
O. Efendiyev was awarded the Emblem of “Glory” in 1986 and for his contribution to the development of science in Azerbaijan on February 14, 2004, under the decree of the President of the Republic of Azerbaijan Ilham Aliyev he deserved "Glory" order.
Corresponding member of Azerbaijan National Academy of Sciences Ogtay Efendiyev died on February 26, 2013 in Baku.