Big Brother 2009, also known as Big Brother 10, was the tenth series of the British reality television series Big Brother. It began on 4 June 2009 and was aired on Channel 4 and E4 for 93 days, concluding on 4 September 2009 when Sophie "Dogface" Reade was crowned the winner with 74.4% of the viewer's vote. The format of the programme remained largely unchanged from previous series; a group of people, referred to as housemates, are enclosed in the Big Brother House under the surveillance of cameras and microphones. Each week, the viewers decide which of a selection of housemates is evicted and, in the final week, one housemate is voted as the winner.