Leonid Andreyev with painting of Demon (drawn by himself), 1910
L. Andreyev (1871-1919) was a Russian writer of the Silver Age. He is considered to be the founder of Russian expressionism. His pre-revolutionary stories (“The Red Laugh”, “The Seven Who Were Hanged”) represent not only his democratic ideas, but also a very special (a bit insane) spirit of the epoch. Andreyev's style is quite special because it is full of religion, mysticism and psychiatry; pessimism about life and human nature.
No wonder that Lovecraft liked him.