John von Neumann (* December 28th, 1903 in Budapest, Austria-Hungary as János Lajos Neumann) is a Hungarian-US-American Mathematician and polymath.
He was a Wunderkind: At the age of six, he had mastered Ancient Greek, at the age of eight calculus.
During 1921-27, he studied chemical engineering and Mathematics in Berlin, Zürich, Budapest, and Göttingen, at the end under David Hilbert. During 1928 to 1933, he was (the youngest) Privatdozent (professor) of the Berliner Universität. Since 1933, he worked at the newly founded Institute for Advanced Study in Princeton as Professor for Mathematics. Among his colleagues there were Albert Einstein and Hermann Weyl. Like these, he emigrated permanently to the USA after Adolf Nazi took over in 1933. During 1936-40, he developed the John von Neumann algebra.
Except with Mathematics (both the pure and applied one) he is also occupied with Physics (especially Quantum mechanics) and Logic - but also with classical history. In 1928, he started the Field of game theory.
At the marriage with his first wife Marietta in 1929, John von Neumann converted to Catholicism. They separated at November 2nd, 1937. On November 17th, 1938 he married Klara Dan.
Before World War II started, he said regarding France: "Oh, France won't matter."