János was born on October 13th, 1911 in Mosonmagyaróvár. János' father was János Körtvélyesi and his mother was Rozália Darázs. He had two brothers and four sisters, named István, József, Teréz, Mária, Anna and Vilma. He was the fourth oldest of the seven children. He died at the age of 76 on April 11th, 1988.