Hugo Steinhaus (1887–1972) was a professor of mathematics at the University of Lwów (now Lviv, Ukraine), where he helped establish what became known as the Lwów School of Mathematics. He is credited with "discovering" Stefan Banach, a prodigy autodidact. Together they contributed to functional analysis by developing the uniform boundedness principle, also known as the Banach-Steinhaus theorem. After World War II, Steinhaus played an important role in establishing a mathematics department at the Wrocław University. Author of around 170 scientific articles and books, Steinhaus left a legacy in several branches of mathematics, including functional analysis, mathematical logic, geometry, and trigonometry. He is also considered a pioneer in game theory and probability theory. (Full article...)