Lionel is the father of Lex and Lena Luthor.
Other Personas of Lionel Luthor
History
CREATORS: Jerry Siegel, Kurt Schaffenberger
FIRST APPEARANCE/DEATH APPEARANCE: Superman's Girl Friend, Lois Lane #23 (February, 1961)
FIRST APPEARANCE (POST-CRISIS): Lex Luthor: The Unauthorized Biography #1 (1989)
LAST APPEARANCE (POST-CRISIS): Superman: Secret Origin #2 (December, 2009)
FIRST APPEARANCE (POST-FLASHPOINT): Superwoman #6 (March, 2017)
DEATH APPEARANCE (POST-FLASHPOINT): Justice League Vol 4 #1 (August, 2018)