Short answers, pulled from the story.
Leonid Andreyev was a Russian playwright, novelist, and short-story writer born in Oryol, Russia, and considered a father of expressionism in Russian literature. He is regarded as one of the most talented representatives of the Silver Age literary period. His style combined realist, naturalist, and symbolist elements, and his debut collection sold a quarter-million copies in 1901.
He Who Gets Slapped, completed in August 1915, is regarded as Andreyev's finest work and is his most internationally performed play. It premiered at the Moscow Art Theatre on the 27th of October 1915, reached Broadway in 1922 in a translation by Gregory Zilboorg, and was adapted into a popular MGM film in 1924.
Gorky read Andreyev's first published short story in 1898 and recommended he focus on literary work. Through Gorky, Andreyev joined the Moscow Sreda literary group and published widely in Gorky's Znanie collections. The friendship helped transform Andreyev from a police-court reporter into a recognized literary figure.
Andreyev moved to Finland in 1917 after viewing the Bolsheviks' seizure of power as catastrophic. From his house there he wrote manifestos against Bolshevik excesses. He died in Finland on the 12th of September 1919, spending his final years in bitter poverty.
Copies of Andreyev's The Seven Who Were Hanged and The Red Laugh were found in H. P. Lovecraft's library after his death. Robert E. Howard ranked Andreyev among the seven most powerful writers of all time. Andreyev's work reached American horror writers largely through the wave of English translations published between 1914 and the late 1920s.
Andreyev had two sons with his first wife Alexandra Veligorskaia: Daniil Andreyev, who became a poet and mystic and wrote Roza Mira, and Vadim Andreyev, who became a poet and lived in Paris. After Alexandra's death in 1906, Andreyev kept Vadim with him and sent Daniil to live with Alexandra's sister.