b. Kraków, Poland, 1892; d. Lwów, Poland, 1945
Functional analysis; real analysis; measure theory;orthogonal series; set theory; topology
Banach was the son of Katarzyna Banach and Stefan Greczek. As his parents were unmarried and his mother was too poor to support her son, he was brought up mainly in Kraków by a foster mother, Franciszka Płowa.
After graduating from high school in 1910, Banach enrolled at the Lwów Polytechnic in the Faculty of Engineering. Two years after his studies were interrupted by the outbreak of World War I, Banach returned to Kraków, where on a summer evening in 1916 he was “discovered” by Hugo Steinhaus, who overheard the words “Lebesgue integral” and brought him to Lwów. Steinhaus considered this ...