| You gotta spin it to win it|
|Stop the presses!|
|We want pictures|
It was set up under the 1980 Broadcast Act by the Thatcher Conservative government, as an unusual compromise between creating a new commercial broadcaster that is funded by advertising, and expanding public broadcasting. This setup of an independently publicly-owned but completely-commercially funded without any support from the government is pretty unique. It is also unusual as it was one of the first publisher-broadcaster, as in it doesn't make its own programmes. Instead the broadcaster commissions and purchases programmes from various outside commercial production companies. Examples of this include ITN for its news, under the banner of Channel 4 News, Yorkshire Television (now ITV Productions) for its infamous gameshow Countdown and production company Mersey Television whom for 21 years created the channel's flagship soap, Brookside.
Channel 4 went to air on 2 November 1982 with the first programme being Countdown. Viewers would eventually follow over the years with Comic Strip presents and Brookside giving the channel a 4.4% audience share. In 1987 Richard Attenborough became Chairman with advertising revenue for the first time exceeding costs providing a £20 million profit, allowing the establishment of Channel 4 International and Channel 4 Films. The 1990 Broadcasting Act preserved Channel 4's publicly owned status with the establishment in 1993 of The Channel Four Corporation, which would allow the corporation to sell its own airtime, instead of asking the local ITV franchises to do it on its behalf.
Today in 2021, the Channel Four Corporation consist of the six nationwide free-to-air TV channels; the flagship channel Channel 4, youth channel E4, the film channel Film4, mature audience channel More4, MTV-like 4Music, catch-up channel 4seven and the online free advertising-funded streaming service All4. It also supports the British film industry through it Film4 Productions subsidiary.
Ooh er, missus
Channel 4 is well known for pushing the envelope broadcasting and being under ire of Mary Whitehouse. In the early years, it broadcasted a series of late night adult arthouse films under the banner of red triangle which were known for a level of nudity and violence. Channel 4 also got into a bother with the tabloid media in the early 1990s, with popular music show The Word over some controversial material. Other debateable programming throughout its history included Chris Morris' mockumentary Brass Eye, Russell T Davies' gay drama Queer as Folk and Charlie Brooker's anthology Black Mirror. In 2006, it did a themed week of programmes under the title of "Wank Week", including a "Masturbate-A-Thon". 
The problem which people moaning about the questionable content is that under Channel 4's remit, it has to be controversial in first place. Its purpose as it states is to: "representing unheard voices, challenging with purpose and reinventing entertainment."  
Highs and lows
Channel 4 is known for generally respectable news and documentaries such as Unreported World, Cutting Edge and Equinox, many of which have been rebroadcasted on other channels worldwide such as PBS and the ABC. The channel’s investigative documentary programme Dispatches, has given out some honourable hard-hitting journalism. Notable episodes include; The Committee, about a high level conspiracy between the security forces and loyalist paramilitaries to murder IRA suspects in Northern Ireland, MMR, what they didn’t tell you, about Andrew Wakefield and his links to the antivax movement , Undercover Mosque, about Islamic extremism in mosques in Birmingham and Inside Britain's Israel Lobby, about links between Israeli friendship organisations and their ties to the British government. 
Also, starting with The Comic Strip Presents... it brought the new genre of alternative comedy outside the London comedy circuit, which replaced the stereotypical working men's clubs with their mother-in-law jokes of the 1970s. This genre led to the channel being the home to award-winning comedies such as; Smack the Pony, The IT Crowd and Father Ted. Notable faces of the channel are; comedian and writer Simon Pegg, actress Anna Friel, who notability gave the first pre-watershed lesbian kiss on British television in 1994,  presenter Denise van Outen and personality Sasha Baron Cohen, who is known his alter ego Ali G their big breaks.
Channel 4's subsidiary film department Film4 Productions  has produced, co-produced, or supported many major British or international films of the last 40 years. This includes for example; My Beautiful Laundrette, Trainspotting, Four Weddings and a Funeral (which made Hugh Grant a household name), East is East and Slumdog Millionaire. Many of them have received many international awards including the Academy Awards and BAFTAs.
On the other hand, it does broadcasted some really crap programmes. The channel is the original home of reality TV show Big Brother, dating gameshow Naked Attraction and property porn Location, Location, Location. It also has been been home to documentaries including the unscientific Great Global Warming Swindle, and launched the career of Gillian McKeith, with You Are What You Eat.
Sianel Pedwar Cymru
One of the reasons for the creation of Channel 4, is to allow those who speak Cymraeg in the "Land of my Fathers", a sensible time to hear it. Which led to the creation of their own channel, S4C. Previously Welsh speakers had to wait until after hours to have a chance of someone say, "Noswaith dda, a chroeso i ... (Good evening, and welcome to...)". Pressured by Welsh nationalists, the government was force to create S4C and it was thought at the same time, use the existing radio bandwidth to create a new broadcaster.
It is doing well, so lets privatise it
Despite the Channel Four Corporation is making a profit, in 2020 it made profits of £74 million on revenue of £934 million.  It is supporting local talent and local production companies, and costing the public absolutely nothing, the current Conservative government wish to privatise it. The culture secretary Oliver Dowden claiming that the current model of an advertising-funded broadcaster delivering free-of-charge over the air or the tube is unsustainable in the era of streaming services like Netflix.  According to The Telegraph, the Conservatives did tried to privatise it 2014 as part of the government's austerity drive, however it was blocked by Vince Cable.  Rumours are floating around that the government is trying to flog it to American broadcasting corporation, Discovery. 
- RTÉ, Ireland's public broadcaster
- CBC, Canada's public broadcaster
- National Public Radio and Public Broadcasting Service, the public radio and television stations in the United States.
- Russia Today, not-exactly-public Russia-based television.
- More tossers on TV, The Guardian
- Channel 4's Purpose & Vision
- Ofcom - Broadcasting Licence - Channel 4
- Brian Deer's 2004 film on Andrew Wakefield - full film, YouTube
- Dispatches: Inside Britain's Israel Lobby 2009, Youtube
- "When Anna and Beth kissed Margaret: Anna Friel plays Brookside's lesbian pin-up. Monique Roffey met her" The Independent
- Film4 Productions
- Channel 4 Annual Report 2020
- UK government mulls Channel 4 privatisation Channel 4 News
- Government denies ‘current’ plans to sell off Channel 4, The Guardian
- Discovery reportedly eyeing Channel 4 takeover, Digital TV Europe