László was born on June 24th, 1941. László's father was Dániel Körtvélyesi and his mother was Terézia Bíró. His paternal grandparents were Dániel Körtvélyesi and Eszter Módra. He had a brother named Dániel. He was the younger of the two children. He died at the age of 53 in September 1994.