Channel 4

Channel 4 is a British public-service television network. Although its funding is commercial, it is owned by a public body. It came into existence to break the duopoly then held by the BBC & ITV, its commercial rival.

Channel 4, and its sister network E4, air a large number of American programming, much of it aimed at younger demographics. Channel 4 broadcast hits such as Friends, Will & Grace, Home Improvement & Roseanne.

Channel 4 bought The Big Bang Theory in June 2007, it began airing the show in February 2008 on E4.

E4

E4 is the digital network from E4, it targets a younger demographic than Channel 4 and thus features less factual programming than its parent. E4 airs "first look" features, showing the next episode of popular shows before they air on the terrestrial channel.

The Big Bang Theory got its UK premiere in February 2008 on E4. Season 2 premiered in November 2008 and continued in March 2009.