of Broadcasting House for outside live broadcasts is common, allowing for a larger audience and/or a bigger stage for a performance or demonstration. The show often takes an active part in events such as Comic Relief/Sport Relief and Children in Need. Cross-promotion of other BBC shows is common, although under BBC rules the show cannot give the BBC preferential coverage. Typically the show airs in a 7pm timeslot on BBC One, however it is occasionally moved later in the evening or to BBC Two to allow BBC One to broadcast extended breaking news coverage or due to overrunning sports events such as Wimbledon. History The One Show was initially commissioned for a four-week trial run. It was broadcast on weeknights at 6:55 pm between 14 August and 8 September 2006. The programme was billed as a topical magazine show that was to showcase stories of interest from around the United Kingdom. The trial was hosted by Adrian Chiles and Nadia Sawalha, featuring reports from a variety of people across the UK. The show was intended to be an updated version of the BBC news magazine show Nationwide (1969–83). After favourable viewing figures for the pilot, the show returned for a full series after being revamped on 9 July 2007. Team members were Adrian Chiles, studio presenter, Hardeep Singh Kohli, head roving reporter, and 13 other reporters or contributors. A number of changes were made to the format. The show was moved from Birmingham to London. Sawalha was replaced by Myleene Klass. Klass then left in August to give birth to her first child, and was replaced by Christine Bleakley. The line-up was completed by the addition of a new team of reporters. The show replaced Real Story, and Holiday. The show's 400th episode aired on 18 March 2009; this was an hour in length instead of the usual 30 minutes. From September 2009, The One Show included a 60-minute episode every week, after successfully trying the format in May 2009. The hour-long format continued until December 2009, and was revived in April 2011. On 13 April 2010, it was announced the show was being revamped with an hour-long Friday episode, to be hosted by Chris Evans. He was not due to start until after the summer break, but prior to this, both Chiles and Bleakley left the show. Chiles departed first, this being announced on 19 April, his last appearance