Big Brother is a BAFTA Award-winning British reality television game show in which a number of contestants live in an isolated house for several weeks, trying to avoid being evicted by the public with the aim of winning a large cash prize at the end of the run. It is the British version of the Dutch Big Brother television format, which takes its name from the character in George Orwell's 1949 novel Nineteen Eighty-Four.
Big Brother, along with its spin-off series Celebrity Big Brother, was originally broadcast on Channel 4 from 18 July 2000 until 10 September 2010, after which it was dropped from Channel 4's schedules due to declining ratings. The rights to the programme were acquired by Channel 5 in a two-year contract with Endemol to air on the main channel and subsidiary channel 5*. The re-launched version premiered on 18 August 2011 with a back-to-back series of Celebrity Big Brother and Big Brother.
The host of Big Brother for the duration of its run on Channel 4 was Davina McCall, who was replaced by Brian Dowling when the show moved to Channel 5. Marcus Bentley has narrated the show since its inception on Channel 4. Spin-off shows that co-existed with the Channel 4 series were presented by Dermot O'Leary, Russell Brand, George Lamb and Emma Willis, who returned to present the only spin-off show Big Brother's Bit on the Side alongside Jamie East and Alice Levine when the show began on Channel 5. On 2 April 2013, it was announced that Willis would be the main Big Brother presenter.