Gordon Lethbridge-Stewart
Gordon James Lethbridge-Stewart — or Gordy, as his mother called him — was the son of Kate Lethbridge-Stewart and Jonathan James. He was the grandson of Fiona and Alistair Gordon Lethbridge-Stewart. Doris Lethbridge-Stewart was his step-grandmother. (HOMEVID: Downtime; PROSE: Downtime; TV: Battlefield)
Gordon was born on 25 September 1990. (PROSE: Of the Future) He was brought up by Kate as a single parent, initially aboard a narrow houseboat moored on an English canal. His father, Jonathan, chose not to be a part of his and his mother's lives after Kate refused to marry him. (PROSE: Downtime)
Gordon was nearly five years old before he met his grandfather, Alistair, Kate having kept her pregnancy and Gordon's existence a secret from her father. Following recent events at New World University, Gordon acquired an imaginary friend called Danny and mentioned this on first meeting his grandfather. (HOMEVID: Downtime)
Gordon's first name was his grandfather's middle name, and great-grandfather's first name. His middle name was his father's surname. (HOMEVID: Downtime) He became the third Gordon Lethbridge-Stewart in his recent family history. (PROSE: The Forgotten Son)
In October 2003, Beth babysitted Gordy when Kate answered a call for help from Douglas Cavendish. (HOMEVID: Dæmos Rising)
Over the years he became very close to his cousin, Conall Lethbridge-Stewart. In 2008, they celebrated their eighteenth birthdays with great abandon, much to their parents' disapproval. (PROSE: Acceptance, and then Understanding)
Gordon gained a sibling later in life on his mother's side. (TV: Death in Heaven)
Gordon cooked for the family one evening. His mother worked late and hoped that there would not be any leftovers. (AUDIO: Power Cell)
Behind the scenes
The in-universe article A Brief History of the Lethbridge-Stewarts, available as a download from the Lethbridge-Stewart website, says Gordon Lethbridge Stewart III "is making waves of his own". Because it is non-narrative, it is not a valid source on this wiki.