Lev Nikolayevich Gumilev (also Gumilyov; ; 1 October 1912 – 15 June 1992) was a Soviet historian, ethnologist, anthropologist and translator. He had a reputation for his highly unorthodox theories of ethnogenesis and historiosophy. He was an exponent of Eurasianism. Life Gumilev's parents, two prominent poets Nikolai Gumilev and Anna Akhmatova, divorced when he was 7 years old and his father was executed by the Cheka when he was just 9. Gumilev spent much of his adulthood, from 1938 until 1956, in Soviet labor camps. He was arrested by the NKVD in 1935 and released, but rearrested and sentenced to five years in 1938. Osip Mandelstam's "Stalin Epigram" is said to have played a role in his arrest. After release, he joined the Red Army and took part in the Battle of Berlin of 1945. However, he was arrested again in 1949 and sentenced to ten years in prison camps. Aiming to secure his freedom, Akhmatova published a dithyramb to Joseph Stalin, which did not help to release Gumilev, although it possibly prevented her own imprisonment. The Soviet secret police had already prepared an order for her arrest, but Stalin decided not to sign it. Relations between Gumilev and his mother became strained, as he blamed her for not helping him enough. She described her feelings about her son's arrest and the period of political repressions in Requiem (published in 1963). After Stalin's death in 1953, Gumilev joined the Hermitage Museum, whose director, Mikhail Artamonov, he would accept as his mentor. Under Artamonov's guidance, he became interested in Khazar studies and in steppe peoples in general. In the 1950s and 1960s, he participated in several expeditions to the Volga Delta and to the North Caucasus. He proposed an archeological site for Samandar as well as the theory of the Caspian transgression in collaboration with geologist Alexander Aleksin as one of the reasons for Khazar decline. In 1960, he started delivering lectures at Leningrad University. Two years later, he defended his doctoral thesis on ancient Turks. From the 1960s, he worked in the Geography Institute, where he would defend another doctoral thesis, this time in geography. Although the official Soviet authorities rejected his ideas and banned most of his monographs from being published, Gumilev came to attract much publicity, especially in the Perestroika years of 1985–1991. As an indication of his popularity, the Kazakh president Nursultan Nazarbayev ordered the L. N.