Casualty (TV series) staff and patients of the hospital's Accident and Emergency Department. The show has very few ties to its sister programme "Holby City", which began as a spin-off from "Casualty" in 1999, set in the same hospital. "Casualty" is shown weekly on a Saturday evening, which has been its time slot since the early 1990s. "Casualty"s exterior shots were mainly filmed outside the Ashley Down Centre in Bristol from 1986 until 2002 when they moved to the centre of Bristol for just over nine years. In 2011, "Casualty" celebrated its 25th anniversary; following that, for the Bristol finale, they filmed the
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