István was born on May 2nd, 1783 in Földes. István's father was János Körtvélyesi and his mother was Anna Szabó. His paternal grandparents were Zsigmond Körtvélyesi and <Unknown>. He had a brother and a sister, named József and Zsuzsanna. He was the oldest of the three children. He died at the age of 56 on April 19th, 1840 in Földes.