Marian Rejewski, a Polish mathematician who with fellow Poles Henryk Zygalski and Jerzy Różycki made a huge effort by solving the Enigma cipher machine afther it was captured on the way from Germany to the Eastern Front by mail giving their results to the code breakers of Bletchley Park, England.
Without their efforts WW2 could have gone bad.
The staue now stands in the center of Bydgoszcz, Marian Rejewski's birthplace.