Casualty @Holby City(2005)

Casualty@Holby City brings together two of the BBC's longest-running medical dramas in special crossover episodes. Casualty premiered in 1986 as a fast-paced accident and emergency series, while its spin-off Holby City launched in 1999 to explore hospital life beyond the A&E department. The first full crossover aired on Christmas Eve 2004, weaving storylines and characters between both shows. By late 2005, four crossover specials had been broadcast across nine episodes, creating dramatic moments that united the two casts and their interconnected worlds. Though the shows have continued to share characters and plots in subsequent years, they abandoned the Casualty@Holby City branding for later collaborations.