"New Tricks" began as a one-off episode broadcast on 27 March 2003. This attracted sufficient viewers for the BBC to commission a series of six episodes, which began on 1 April 2004. Eight-episode series were subsequently commissioned for 2005, 2006 and 2007. A fifth series was commissioned by the BBC after the audience share rose week upon week for the previous series. In 2007, an episode from the fourth series received viewing figures of 9.25 million, becoming the second most-watched programme on BBC One that week, and the most-watched "New Tricks" episode to that point. The fifth series continued this good run – on two occasions it was the most-watched programme in Britain for the week, and the seventh episode gained a new series high rating of 9.36 million—second only to the "X Factor" that week. The fifth series aired from 7 July to 25 August 2008. The sixth series finished location filming on 8 May 2009 in central London and began airing on 16 July 2009. The opening episode of series six was watched by 8.07 million, despite clashing with Five's "The Mentalist" (1.64m) and ITV's "Living with Michael Jackson" (3.64m). The second episode clashed with "The Mentalist" and the relaunch of "The Bill" on ITV, and was watched by 7.59 million.