Ismayil Huseynov was born in 1910. In 1931, he graduated from Azerbaijan State University, Faculty of History. From 1933 to 1936, he did postgraduate studies at Moscow People`s Institute. From 1934 to 1941, he served as an editor and translator at USSR Soviet of People`s Commissariat, research fellow at Material Culture Institute of USSR Academy of Sciences, scientific adviser at All-Union State Library named after V.I.Lenin, and research fellow at the Institute of History, USSR Academy of Sciences. In the 1930s, Ismayil Huseynov published several books of poems. In 1941, he defended a PhD thesis, and returned to Baku. In 1941-1942, he worked as director of the Institute of History, Azerbaijan branch of the USSR Academy of Sciences. From 1942 to 1944, he participated in the Great Patriotic War, and was employed as an editor at a military newspaper. In 1947, he defended a ScD thesis in Moscow to become the first Azerbaijani to achieve a ScD degree in history. In 1949, he was elected a corresponding and in 1958 a full member of the Academy of Sciences of Azerbaijan SSR. In 1969, he was awarded the title “Merited Scientist” of Azerbaijan SSR. From 1944 to 1958, Ismayil Huseynov served as deputy director of the Institute of History of the Communist Party under the Central Committee of the Communist Party of Azerbaijan, from 1958 to 1960 as director of the Institute of History, Academy of Sciences of Azerbaijan SSR, as department head and vice-rector at Azerbaijan State Pedagogical Institute and Azerbaijan State University. From 1960 to 1968, he worked as academic secretary at the Department of Public Sciences, Academy of Sciences of Azerbaijan SSR. In 1968, he was made a professor at the Department of History of USSR, Azerbaijan State University. His research interests laid in the establishment of socialism in Transcaucasia, and development of socialism in Azerbaijan. Ismayil Huseynov played an invaluable role in preparing highly-qualified historians.