Holby fictional hospital within the city in which "Casualty" and "Holby City" are set. It is based on the Bristol Royal Infirmary which the original script writers spent time observing in the 1980s in order to garner ideas for "Casualty". Although both shows are set in the same hospital, "Casualty" is primarily filmed in Cardiff, whilst "Holby City" is filmed in Hertfordshire at BBC Elstree Centre. The indoor shots for the first series of "Casualty" were filmed at BBC Television Centre in London. The exterior shots of the hospital used in "Casualty" were formerly filmed at the City of Bristol College;
Holby City succeeded by Kathleen Hutchison from 2002 to 2004, Richard Stokes from 2004 to 2006, McHale from 2006 to 2010, Belinda Campbell from 2010 to 2011, Johnathan Young from 2011 to 2013, Oliver Kent from 2013 to 2017 and Simon Harper from 2017. Since the show's initial development, it has become a weekly fixture in the schedule. Holby City airs once a week, all year round, and each series now contains 52 episodes. The show follows the lives of medical and ancillary staff at the fictional Holby City Hospital. It began with eleven main characters in its first series, all of