Short answers, pulled from the story.
Anton Chekhov was a Russian playwright and short story writer who lived from 1860 to 1904. Literary critic Daniel S. Burt named him one of the greatest and most influential writers of all time; Raymond Carver praised the "awesome frequency" with which he produced masterpieces. Along with Henrik Ibsen and August Strindberg, Chekhov is considered one of three seminal figures in the birth of early modernism in the theatre.
Chekhov's four major plays are The Seagull (written in 1895), Uncle Vanya (written in 1897), Three Sisters (written in 1900), and The Cherry Orchard (written in 1903). All four were produced or premiered by Konstantin Stanislavski's Moscow Art Theatre. Chekhov described their approach as a "theatre of mood" with a "submerged life in the text."
Chekhov's gun is a dramatic principle requiring that every element in a narrative be necessary and irreplaceable. Chekhov stated it as: "If you say in the first chapter that there is a rifle hanging on the wall, in the second or third chapter it absolutely must go off." The principle emerged from the period following his play Ivanov in 1887.
Chekhov traveled to Sakhalin Island, a Russian penal colony north of Japan, to interview thousands of convicts and settlers for a census. He spent three months there and witnessed floggings, embezzlement of supplies, and forced prostitution of women. His findings were published in 1893 and 1894 as Ostrov Sakhalin (The Island of Sakhalin), a work of social science.
Chekhov died on the 15th of July 1904 at the age of forty-four in Badenweiler, a German spa town in the Black Forest, after a long fight with tuberculosis. His last recorded words were "Ich sterbe" (I'm dying), followed by a glass of champagne. He was buried beside his father at the Novodevichy Cemetery in Moscow.
Chekhov's influence entered American theatre through Stanislavski's system of acting, with its emphasis on subtext. The Group Theatre developed this subtextual approach, influencing Clifford Odets, Elia Kazan, and Lee Strasberg. Strasberg's Actors Studio and Method acting in turn shaped actors including Marlon Brando and Robert De Niro.