Today’s Google Doodle celebrates Stefan Banach, one of the 20th century most influential mathematicians.

Banach was an original member of the Lwów School of Mathematics and founder of modern functional analysis.

Banach was born in Krakow, which was then part of the Austro-Hungarian Empire, on 30 March 1892. He never knew his mother, and his father sent him to be raised by a family in the city.

Banach was interested in maths from a young age. He used to solve problems during breaks and after school with his best friend, Witold Wiłkosz, who also went on to become a famous mathematician.

When the First World War broke out Banach was excused from military service due to his left-handedness and poor vision.

During the war he met Hugo Steinhaus one of the most celebrated mathematicians of the time, in Krakow, and Steinhaus became fascinated with him and his abilities, given that he was largely self-taught.

Steinhaus was an early founder of game and probability theory, but called Banach his “greatest scientific discovery”.