26 January 1926: First public demonstration of television to members of the Royal Institution by John Logie Baird in his London Laboratory.
24–27 May 1927: Baird demonstrates long distance transmission of television pictures over telephone lines from London to Glasgow (438 miles).
20 September 1927: Baird makes first electronic image recordings onto ordinary 78 rpm gramophone records. He called this system “Phonovision”.
30 December 1927: Baird demonstrates “Noctovision” (infra-red television) to the Royal Institution.
8 February 1928: Baird successfully transmits television pictures across the Atlantic.
3 July 1928: Baird demonstrates colour television.
10 August 1928: Baird demonstrates stereoscopic (3D) television.
5 March 1929: Baird broadcasts television using the BBC’s London transmitter.
30 September 1929: Baird begins regular experimental 30-line television broadcasts. Because there is only one radio transmitter available, sound and vision are transmitted alternately for 2 minutes each.
14 March 1930: Simultaneous sound-and-vision 30-line television transmissions are made possible by a new transmitter (Brookman’s Park).
14 July 1930: First British television drama: Pirandello’s The Man with a Flower in his Mouth.
March 1931: The Gramophone Company (HMV) and Columbia Graphophone Company merge to form a new company, Electrical and Musical Industries (EMI).
3 June 1931: First television outside broadcast—Baird televises the Derby using a mirror drum camera mounted in a caravan.
22 August 1932: The BBC takes over programme-making for the 30-line television service.
September 1932: EMI secretly demonstrate their first electronic television camera.
24 January 1934: EMI demonstrates a workable electronic television camera. They name their camera the ‘Emitron’.
31 January 1935: The Television Advisory Committee, under Lord Selsdon, take evidence on the relative merits of the various worldwide ‘high definition’ (240 lines or greater) television systems. They recommend that both the Baird 240 line mechanical system and the Marconi-EMI 405 line electronic system be developed as alternatives for the proposed new London television station.
2 November 1936: BBC Television begins broadcasting regular high-definition programmes from Alexandra Palace to the London area. The non-compatible Baird and Marconi-EMI systems are used on alternate weeks.
6 February 1937: The Baird system is abandoned on the advice of the Television Advisory Committee.
12 May 1937: First major electronic television outside broadcast: the Coronation of King George VI. Nine thousand TV sets are sold in the London area.
1 September 1939: British television is shut down immediately at the advent of WWII. It is estimated that there are 20,000 TV sets in Britain at this time.
23 December 1941: Baird gives first demonstration of 600-line electronic stereoscopic television in colour.
7 June 1946: BBC television re-opens after the war.
July-August 1948: London hosts the 1948 Summer Olympics, the first Olympic tournament to be broadcast to home television.
17 December 1949: BBC TV Midlands transmitter opens.
27 August 1950: First live link from the continent (Calais to London) lays the foundation for the later Eurovision network.
12 October 1951: BBC TV North transmitter opens, serving the North of England.
15 January 1952: BBC TV Scotland transmitter opens.
2 June 1953: Biggest outside broadcast to date: Coronation of Queen Elizabeth II.
22 September 1955: Commercial television (ITV) starts broadcasting in the London area.
21 July 1955: BBC TV Northern Ireland transmitter opens. 95% of the UK can now receive BBC television.
October 1958: Videotape recording starts in Britain; prior to this the only way to record programmes has been to use film (telerecording).
11 July 1962: First transatlantic satellite link via Telstar.
16 April 1964: First live link from Japan via Telstar II.
20 April 1964: BBC2 scheduled to open on 625 lines. Massive power failure in West London means that Gala opening night is cancelled. BBC2 opens the following morning, 21 April, with episode of Play School.
2 May 1965: First trans-Atlantic satellite television transmission from the USA is made via the geosynchronous satellite Intelsat I, nicknamed “Early Bird”.
3 March 1966: The Phase Alternating Line (PAL) colour television system is officially adopted for the UK.
1 July 1967: Regular colour transmissions begin on BBC2.
July–August 1968: New ITV contracts start: new companies include London Weekend Television, Thames Television, and Yorkshire Television.
15 November 1969: Regular colour transmissions begin on BBC1 and ITV.
21 July 1969: First live television pictures of men on the moon.
January 1971: The Open University begins broadcasting from the old BBC studios at Alexandra Palace.
29 July 1981: Biggest outside broadcast to date: the wedding of Prince Charles and Lady Diana Spencer (750 million viewers in 74 countries).
1 January 1982: New ITV contracts start. New companies include: Central Television, TVS, and TSW.
2 November 1982: Channel 4 television begins broadcasting.
17 January 1983: BBC Breakfast Time (breakfast television) starts.
2 November 1983: TV-AM breakfast television starts.
6 February 1989: Launch of Sky television (satellite television provider)
29 April 1990: Launch of British Satellite Broadcasting (BSB) (satellite television broadcaster).
2 November 1990: Sky and BSB merge to form BSkyB.
1 January 1993: New ITV contracts start. New companies include: Carlton Television, Meridian Broadcasting, Westcountry Television and GMTV. Old companies lost in the franchise change include: TV-AM, TVS, TSW and Thames.
31 March 1997: Channel 5 begins broadcasting.
1 October 1998: BSkyB begins digital TV transmissions from a new generation of satellites as Sky Digital.
22 October 2002: UK’s Freeview free-to-air digital terrestrial television (DTT) service officially begins
2 February 2004: Merger of Granada Television and Carlton Television is completed. The new company is named ITV plc.
27 May 2006: The BBC begins broadcasting in high-definition (HDTV) on their new subscription channel BBC HD.
17 October 2007: The gradual switch-off of all analogue terrestrial TV broadcasts begins in Whitehaven. The last regions will be switched off in 2012.
25 December 2007: The BBC launches iPlayer, an internet service for watching previously aired TV shows.
January 2008: Warner Home Video announces that it will support only Blu-ray Discs, setting off a chain reaction in favour of the format.
6 May 2008: The Freesat satellite service starts, including the first non-subscription HDTV channels.
30 March 2010: Freeview HD is launched across the UK, featuring the new Channel 4 HD.
1 October 2010: Sky launches Europe’s first stereoscopic (3DTV) television channel.
28 February 2011: Product placement is permitted on UK television for the first time.
2012–2013: The BBC sells Television Centre, and moves most of its operations from Television Centre to other BBC sites, particularly Broadcasting House and MediaCityUK in Salford. ITV plc also relocates many of its studios and operations from the Old Granada Studios to MediaCityUK, including the Coronation Street set.
4 January 2012: Netflix launches its movie and TV streaming service in the UK.
July-August 2012: London hosts the 2012 Olympics, and the BBC wins the UK contract to broadcast all Olympic tournaments up to 2020. Coverage of the Paralympic Games is broadcast on Channel 4 for the first time.
24 October 2012: The switch-off of all analogue terrestrial TV broadcasts completes in Northern Ireland.
2013–2016: Phase one of the Local Digital Television Programme Services (L-DTPS) sees new local television services launch in 21 local areas, licenced by Ofcom.
14 June 2013: The British Audience Research Board (BARB) announces it will include online viewing through catch-up services in its official viewing figures.
1 August 2015: Launch of BT Sports Ultra HD, the first 4K Ultra HD channel in the UK.
16 February 2016: BBC Three becomes online-only.
1 September 2016: A TV Licence becomes a requirement for watching BBC iPlayer online.
1 January 2017: The BBC commences its renewed Charter, and from April Ofcom becomes the first external regulator for the BBC.
Note: this post was originally published in April 2011 and has subsequently been updated to reflect more recent developments.