Holby City cast as Greg Douglas in series twelve. "Holby City" and "Casualty" are both set in Holby City Hospital, in the fictional county of Wyvern, in the southwest of England close to the Welsh border. The city exterior is represented by Bristol, though "Holby City" is filmed at BBC Elstree Centre in Borehamwood, Hertfordshire. The "Casualty" set in Bristol was not large enough to encompass the surgical ward and operating theatre required for "Holby City", and as a result, some crossover scenes in the first episode had to be shot twice, first on the "Casualty" set and then again at Elstree,
Holby City is limited to "accident of the week" storylines about patients entering hospital, "Holby City" allowed the possibility of storylines about long-term care, rather than immediate life and death decisions. The series was commissioned by BBC One Controller Peter Salmon, and began airing on BBC One on 12 January 1999. Series producer Richard Stokes believes that the series' popularity stems from the fact the hospital setting presents numerous plotline opportunities, explaining: "You have licence to create life-and-death situations every week, something you cannot do in any other set piece. The interaction of the characters can be sexy and social issues also