Lionel Luthor

Lionel Luthor is the father of both Lex and Lena Luthor as well as the husband of Lillian. He passed away some number of years ago and his son inherited his company Luthorcorp.

History
After marrying Lillian, Lionel cheated on her and Lillian found out about it. She also found out about their daughter. Lionel and Lillian decided to adopt Lena so she could still be a Luthor.

Bringing Lena Home.
Lena was brought home by Lillian where she was introduced to her brother Lex. Lionel was unsure about the adoption, but went along with it.

For years Lionel stopped Lillian from ever forming a close relationship with Lena.

Lena thought of her father as a saint because of this.