Shloyme Zanvl Rappoport (1863, Vitebsk –1920, Otwock), better known by the pseudonym S. Ansky (or An-ski), was a scholar who documented Jewish folklore and mystical beliefs.
He was born in Vitebsk, Belarus, then Russia, but travelled around much of the western part of the Russian Empire. Initially writing in Russian, from 1904 he also became known as a Yiddish author.
Initially under heavy influence of the Russian narodnik movement, Ansky was soon interested in ethnography. Between 1911 and the outbreak of the Great War in 1914 he headed ethnographical expeditions to various Jewish towns of Volhynia and Podolia.
He is best known for authoring the play The Dybbuk or Between Two Worlds, which was first staged in the Elyseum Theatre in Warsaw two months after the author's death in Otwock on November 8, 1920 . Ansky was also the author of the song Di Shvue (The Oath), which became the anthem of the Bund party, and several other pieces of literature, both in Russian and Yiddish.
His ethnological collections were locked away in Soviet vaults for years, but some material has come to light since the 1990s. The State Ethnographic Museum at St Petersburg holds a good deal of it.