Gordon Lethbridge-Stewart
Gordon James Lethbridge-Stewart was the son of Kate Lethbridge-Stewart (a/k/a Kate Stewart) and the grandson of Fiona and Alistair Gordon Lethbridge-Stewart. Doris Lethbridge-Stewart was his step-grandmother. (HOMEVID: Downtime; TV: Battlefield)
Gordon was reared by Kate as a single parent, initially aboard a narrow houseboat moored on an English river. His unnamed father chose not to be a part of his and his mother's lives. Gordon was a few years old before he met his grandfather, Alistair, Kate having kept her pregnancy and Gordon's existence a secret from her father. (HOMEVID: Downtime)
Like Anthony Brian Williams whose middle name is his grandfather's first name, Gordon's first name is his grandfather's middle name. (HOMEVID: Downtime; Webcast: P.S.)