Arthur Moritz Schoenflies (German: [ˈʃøːnfliːs]; 17 April 1853 – 27 May 1928), sometimes written as Schönflies, was a German mathematician, known for his contributions to the application of group theory to crystallography, and for work in topology. Schoenflies was born in Landsberg an der Warthe (modern Gorzów, Poland). Arthur Schoenflies married Emma Levin (1868–1939) in 1896, whose sister, the writer Julie, was married to the publisher and docktor Julius Levin. He studied under Ernst Kummer and Karl Weierstrass, and was influenced by Felix Klein. He was a great-uncle of Walter Benjamin.