5000 Forint János Neumann

János Neumann — known in the West as John von Neumann — was born in Budapest in 1903, and this coin marks the centenary of his birth. His contributions span the mathematical foundations of quantum mechanics, game theory, and the stored-program architecture that underlies virtually every computer built since the late 1940s. The Hungarian government has long claimed him as a national figure, though he left Hungary permanently in 1930 and spent his most productive decades at Princeton's Institute for Advanced Study.

The Magyar Nemzeti Bank issued this as part of its ongoing commemorative silver program. Neumann died in 1957 of cancer, likely caused by radiation exposure during his work on the Manhattan Project at Los Alamos.