"Torchwood" is an anagram of "Doctor Who". When the first series of Doctor Who (2005) was being made, television pirates were desperate to acquire the preview tapes. One of the people in the office had the idea of labeling the tapes with the anagram "Torchwood" rather than "Doctor Who", as a security measure to disguise the tapes when they were delivered from Cardiff to London. Writer Russell T. Davies liked this idea so much that it later inspired him to use it as a title when creating this spin-off series.
Owen and Suzie are the only members of the Torchwood team never to have had direct contact with the Doctor. Jack has been companion to both the Ninth and Tenth incarnations; Toshiko met the Ninth Doctor while examining the space pig in Doctor Who: Aliens of London (2005); and Gwen and Ianto met the Tenth Doctor through the sub-wave network in Doctor Who: The Stolen Earth (2008).
In certain episodes, Torchwood members use a drug called "Retcon" to wipe the memories of people who know too much about the organization. Retcon is a term derived from "Retroactive Continuity" and is used in serialized fiction, especially comic books, for when new events effectively change or erase the established history of a series.
In several episodes throughout series 1, posters bearing the slogan "Vote Saxon" are visible in several shots, most noticeable in episode 12 (Torchwood: Captain Jack Harkness (2007)) on the door of the dance hall. In series 3 of Doctor Who (2005), which was broadcasting during the same year, "Saxon" was the running keyword arc and the identity of "Mr Saxon" was the subject of the season finale.
Torchwood was the subject of a background arc during the 2006 series of Doctor Who (2005), with most episodes containing at least one reference to the Torchwood Institute, beginning with the 2005 series episode "Bad Wolf" and culminating in the Institute's appearance in "Army of Ghosts" and "Doomsday". The 2006 episode "Tooth and Claw" details the origins of Torchwood. After "Torchwood"'s debut, it was referenced again in the Doctor Who Christmas special, "The Runaway Bride".
Prior to becoming involved in the revival of Doctor Who (2005), Russell T. Davies had conceived of this series as a concept about an alien-fighting team called "Excalibur". After DW became a success, Davies decided to rework the idea as a spin-off, and he latched on to the codeword "Torchwood" for the core organisation.
"Torchwood" is the first Doctor Who spin-off to make it to series, and the first dramatic spin-off of Doctor Who (2005). A failed attempt to spin-off a series from the original Doctor Who (1963) resulted in the television special, K-9 and Company: A Girl's Best Friend (1981), featuring the characters K9 and Sarah Jane Smith. After failing to produce a series, the pilot was broadcast as a seasonal special.
Gwen Cooper is the distant relative of Gwyneth, the servant girl whom The 9th Doctor and Rose Tyler encounter in 1869 Cardiff in Doctor Who: The Unquiet Dead (2005). Gwyneth was also played by Eve Myles.
Jack's primary gun for the series is a Webley Mk VI .455 revolver. The Webley was the standard issue sidearm for the British military from 1887 to 1963. In actuality, Jack's weapon is a Webley Mk IV .38. This is evident in the muzzle diameter and overall frame size of the gun. The Mk VI variant, introduced in 1915, is probably the best-known model. The Mk IV variant rose to prominence from 1899-1902 and is still in use as a police service weapon in many countries.
The child taken away with the fairies is Lara Phillipat, who's first appearance in the Doctor Who world is in Doctor Who, ep 7, ( The Idiot's Lantern) 2006, where she appears as a guest watching the Queens coronation.
In the backstory behind Jack Harkness and the new Torchwood: Following the battle of Canary Wharf, Jack Harkness reorganized the Torchwood Institute (Which Queen Victoria founded to fight The Doctor as well as defending England from future alien attacks) and changed the organization in honor of The Doctor. See: Doctor Who: Tooth and Claw (2006). Doctor Who: Doomsday (2006) and Doctor Who: The Sound of Drums (2007).
The series is not just about Captain Jack Harkness and the Torchwood team battling hostile extra terrestrials and supernatural threats. The series is also about Gwen Cooper, as she struggles with Torchwood life and keeping it a secret from Rhys and her defiance of Captain Jack Harkness and questions and challenges his leadership.
Unlike Doctor Who (2005) (TV Series) which this series is a spin-off of and it is set in the same universe and unlike that series. This series had bad language and sex. But, when Jack, Gwen and Ianto appear in the 2-part season finale of Doctor Who's 4th season. They don't cuss and non of them are seen having sex. This is due to the fact that Doctor Who is a family show.
Eve Myles had played another character called Gwen prior to the series. In the TV movie EastEnders: Dot's Story (2002) (TV Movie) Eve Myles played the younger version of Dot Cotton's friend Gwen whom Dot Cotton stayed during World War II.
Gwen keeping Torchwood a secret from Rhys was influenced by True Lies (1994). In that film, Arnold Schwarzenegger stars as spy whom has kept him being a spy a secret from his wife (Played by Jamie Lee Curtis).
There was a recurring storyline throughout the series, which Gwen struggled with both her personal life and being a member of the Torchwood team and keeping it a secret from Rhys. The recurring storyline would conclude with Rhys learns about Gwen's affair with Owen Harper in Day One (#1.2) and Rhys finally learning the truth about Torchwood when he spots Gwen with the Torchwood team in Meat (#2.4).
In the scene which Owen shoots Jack in Torchwood: Exit Wounds (2008) Gwen punches Jack in the face over his remark about Gwen cheating on Rhys with Owen. Although Jack's remark is uncalled for, but Jack did have a point. Gwen was sexually unfaithful to Rhys.
Russell T. Davies acknowledged that Gwen Cooper is an character that can be loved and hated by fans. Fans of the series whom hated the character hated her mostly due to Gwen cheating on her fiancee Rhys Williams with Owen Harper and treating Rhys like a moron and her defiance of Captain Jack Harness which she questions and challenges his leadership.