Sergei Efron

Sergei Yakovlevich Efron (Russian: Сергей Яковлевич Эфрон; 8 October 1893 – 11 September 1941) was a Russian poet, White Army officer, and the husband of fellow poet Marina Tsvetaeva. While in exile, he was recruited by the Soviet NKVD. After returning to the USSR from France, he was executed.