**Born:** March 30, 1892, in Ostrowsko, 50 kilometers south
of Krakow (Cracow), Austria-Hungary-occupied Poland (now Poland)

**Died:** August 31, 1945, in Lwow (Lemberg, Lviv), Soviet Union (now
Ukraine)

**Accomplishments:** Founded the important modern mathematical field
of functional analysis and made major contributions to the theory of
topological vector spaces. In addition, he contributed to measure theory,
integration, the theory of sets and orthogonal series.

**Stefan Banach**, son of Stefan Greczek, a tax official and, possibly, of
Katarzyna Banach. Who was in fact his mother remains uncertain. Banach
was brought up in Krakow by Franciszka Plowa and received his early education
from a French intellectual, Juliusz Mien, who was the guardian of Plowa’s
daughter. In 1902, Banach finished primary school in Krakow and began his
secondary education at the Henryk Sienkiewicz Gymnasium No. 4 in the same city.
According to one of his colleagues, Banach was very good in mathematics and
natural sciences, but was not interested in anything else. He finished
the Gymnasium in 1910 without distinction. As he felt that nothing new
can be discovered in mathematics, he chose to study engineering at the Lwow
Polytechnic (1910-1916). His father did not want to support him
financially, so he supported himself probably by tutoring. During this
period, he frequently left Lwow to build roads, but also attended mathematics
lectures at the Jagiellonian University in Krakow and taught in local schools.
In the spring of 1916, he met in Krakow, by chance, Steinhaus, a mathematician
who just got a position at Lwow University. Steinhaus, impressed by young
Banach's talent for mathematics, told him about a problem he couldn't solve.
Banach helped Steinhaus and the ensuing paper they wrote together was published
in Krakow in 1918. Since then Banach produced many papers. Also
thanks to Steinhaus he met Lucja Braus, whom he married in Zakopane in 1920.
In the same year, Banach became an assistant to Lomnicki, a professor of
mathematics at Lwow Polytechnic. Lomnicki served as Banach's major
advisor for his doctoral thesis. In 1922, the Jan Kazimierz University in
Lwow awarded Banach his habilitation (a degree allowing to teach at the
university) for a Docent in Mathematics for his thesis on measure theory.
In July 1922, he was appointed Extraordinary Professor. In 1924, he was
promoted to Ordinary Professor (Full Professor). He spent the academic
year 1924-25 in Paris. In 1929, he started, with Steinhaus, the journal
Studia Mathematica. In 1931, he started co-editing, together with Steinhaus,
Knaster, Kuratowski, Mazurkiewicz and Sierpinski, a series titled Mathematical
Monographs. In 1936, Banach gave a plenary address at the International
Congress of Mathematicians in Oslo, Norway. From 1927 until 1934, he
wrote some joint papers with Kuratowski. He also worked with Ulam and
Turowicz. In 1939, Banach was elected President of the Polish Mathematical
Society. After the Soviets invaded Lwow in 1939, Banach was allowed to
continue to hold his chair at the university and he became the Dean of the
Faculty of Science, the university being renamed the Ivan Franko University.
Famous Soviet mathematicians Sobolev and Aleksandrov visited Banach in Lwow in
1940. In the same period, Banach attended conferences in the Soviet
Union.

He was in Kiev when Germany invaded the Soviet Union, but he returned immediately to his family in Lwow. He was arrested, but after few weeks he was released. He also survived the Nazi slaughter of Polish university professors. His advisor Lomnicki was among those who perished. From the end of 1941 through the remainder of the Nazi occupation (July 1944), Banach worked feeding lice in Prof. Weigel’s Institute in Lwow. After the Soviets reentered Lwow, Banach contacted his Soviet friend Sobolev, who wrote about this encounter: "...and despite the grave illness that was undercutting his strength, Banach's eyes were still lively. He remained the same sociable, cheerful and extraordinarily well-meaning and charming Stefan Banach whom I had seen in Lvov before the war. That is how he remains in my memory: with a great sense of humor, an energetic human being, a beautiful soul and a great talent..." Banach died of lung cancer in Lwow in 1945.

**Article by:** J. J. O'Connor and E. F. Robertson

**Copyright Information:**

GAP is Copyright (C) 1986--1997 by Lehrstuhl D für Mathematik, RWTH Aachen,
Aachen. Germany and Copyright (C) 1997-2001 by School of Mathematical and
Computational Sciences, University of St. Andrews, St. Andrews, UK. GAP can be
copied and distributed freely for any non-commercial purpose.

**Books:**

R. Kaluza, The Life of Stefan Banach (Boston, 1996).

S. Ulam, Adventures of a Mathematician (New York, 1976).

**Online Resources:
**Biography:
http://www-gap.dcs.st-and.ac.uk/%7Ehistory/Mathematicians/Banach.html

Photos: http://www-gap.dcs.st-and.ac.uk/%7Ehistory/PictDisplay/Banach.html

Polish postage stamp (look for Banach on the list): http://jeff560.tripod.com/

**Other References:**

Biography in Dictionary of Scientific Biography (New York, 1970-1990).

Biography in Encyclopaedia Britannica