Grandpa Chase is the father of Randolph, Natalie and Frederick Chase, husband of Grandma Chase and grandfather of Annabeth, Aubrey, Bobby, Matthew and Magnus Chase.
Grandpa Chase lived in Boston and at one point married a woman and fathered two sons and a daughter. He lived in a six floor Boston brownstone mansion which he gifted to his oldest son. He and his wife died before meeting their grand children.
Magnus mentioned his grandfather when entering his family's house.
Magnus finds a picture of him and his wife in the mansion's library.
Grandpa Chase is described as an old man with white hair and mustache. He wears glasses.
- He and his wife had a collection of Norse artifacts, a fascination that his eldest son would pick up.