Holby City is a British medical drama television series that premiered on 12 January 1999 on BBC One. The series was created by Tony McHale and Mal Young as a spin-off from the established BBC medical drama Casualty. It is set in the same hospital as Casualty, Holby General, in the fictional city of Holby, and features occasional crossovers of characters and plots with both Casualty (in episodes broadcast as Casualty@Holby City) and the show's 2007 police procedural spin-off HolbyBlue. ni Holby City follows the professional and personal lives of surgeons, nurses, other medical and ancillary staff and patients at Holby General. It features an ensemble cast of regular characters, and began with 11 main characters in its first series, all of whom have since left the show. New main characters have been both written in and out of the series since. In addition, Holby City features guest stars each week, as well as recurring guests that take part in story arcs that span a portion of a series. Occasionally, the recurring guest storylines will span multiple series. Many actors in the series have made prior, minor appearances as both patients and staff members in both Holby City and Casualty - in some instances crediting these former appearances for their later casting as main characters in Holby City.
In casting the first series of Holby City, Young selected actors who were already established names in the acting industry, primarily from a soap opera background. He cast Michael French as Nick Jordan, George Irving as Anton Meyer, Angela Griffin as Jasmine Hopkins, Lisa Faulkner as Victoria Merrick and Nicola Stephenson as Julie Bradford. Young explained: "Soap actors are the best actors. There's been so much snobbery before. The whole thing about typecasting was probably invented by actors who couldn't get other work. From day one I knew I wanted to put on screen people that viewers want to watch. There’s no downside to that." This propensity for hiring established actors continued as the soap progressed, with later roles being awarded to comedian Adrian Edmondson, former film actress Patsy Kensit, and Jesus of Nazareth star Robert Powell. When Jane Asher was cast in the recurring role of Lady Byrne in 2007, Inside Soap magazine asked series producer Diane Kyle whether the production team intentionally sought out "well-known-names", or whether roles simply went to the actor best-suited for the part. Kyle responded: "It's lovely when we have a new member of the cast come in and bring an audience with them. But we want the best actors, and the star names we cast are always the best - which is why we go for them."