"Karl Marx was born at Trier on 5 May 1818, the child of Jewish parents with a long rabbinical tradition on both sides. His grandfathers were rabbis; his father, a well-to-do lawyer, changed his first name from Herschel to Heinrich and adopted Protestantism, which in Prussia was a necessary condition of professional and cultural emancipation. (pg. 96)"
January 1, 1970
https://en.wikiquote.org/wiki/Leszek_Ko%C5%82akowski