On the 19th February 1985, the BBC’s flagship soap opera EastEnders was broadcast for the first time. Now airing four episodes a week, the series has been broadcast continuously ever since and remains one of the most popular television shows in the United Kingdom.

EastEnders was created by Julia Smith and Tony Holland, a producer and script editing partnership who had previously worked together on long-running police drama Z-Cars. In March 1983 they were asked to come up with a bi-weekly evening television drama by David Reid, the BBC’s Head of Series & Serials, who wanted a new show to run 52 weeks a year.

Smith and Holland were both from London, and opted to set the soap in the East End. They based the original twenty-four characters on their own families and people they had met in London’s ‘real’ East End, and contacted casting agencies in search of actors to fill the roles. Their repeated phone calls asking for ‘real East Enders’ provided Smith with the idea for the show’s name.

The show required a huge set to be built at Elstree Studios in Hertfordshire. Meanwhile, composer Simon May created the now-iconic theme tune. This was to play over an aerial view of London pieced together from 800 separate photographs taken from an aeroplane flying 1000 feet over London.

The show was first broadcast on the 19th February 1985 as part of new BBC One controller Michael Grade’s ‘relaunch’ of the channel. The first episode secured an audience of 17 million, which increased to 23 million by the end of the year.

On the 5th February 1924 the BBC ‘pips’ were broadcast for the first time. Five short pips signal the five seconds leading up to the hour, with a slightly longer pip marking the start of the new hour. Although now largely inaccurate as a result of the inherent delay in the encoding, transmission, and decoding of digital radio broadcasts, the pips are still a part of many BBC radio programmes.

The BBC successfully broadcast the chimes of Big Ben for the first time at New Year 1924. This led the Astronomer Royal at the time, Sir Frank Watson Dyson, to suggest that time signals could be broadcast more regularly. Having convinced BBC boss John Reith, the Royal Greenwich Observatory fitted the pendula of two mechanical clocks with electrical contacts that sent a signal to the BBC every second.

The equipment that generated the pips moved from Greenwich in 1939, but the pips are still known officially as the Greenwich Time Signal. The name was even kept after the Greenwich Time Service stopped transmitting the pips in 1990. Since then, the national BBC stations have generated the pips themselves using an atomic clock in the basement of Broadcasting House.

Due to their use as a time signal, the BBC doesn’t allow programmes to broadcast the six pip sequence for any other reason, and used to strongly discourage broadcasters from ‘crashing the pips’ – that is playing any other sound at the same time. Although this rule is now less rigorously enforced on most stations, some Radio 4 listeners still wait with baited breath to hear a presenter accidentally talk over them.

Desert Island Discs is Britain’s longest-running radio programme.

Devised by the English radio broadcaster and producer Roy Plomley in November 1941, each episode of Desert Island Discs features an interview with a celebrity who imagines that they have been cast away on a desert island with only a limited number of home comforts. In the early years they were permitted to choose eight songs to take with them, although a few years after the programme’s inception castaways were also allowed to take one book and one luxury item, in addition to a copy of the Complete Works of Shakespeare and an appropriate religious or philosophical work such as the Bible.

Plomley was commissioned to create the new radio programme by the BBC’s Head of Popular Record Programmes, Leslie Perowne. Just two months after he pitched the idea, he found himself in the bomb-damaged studio at Maida Vale conducting the very first interview with popular entertainer Vic Oliver who chose Chopin’s Étude No.12 in C minor, “Revolutionary”, as his first piece of music.

The first series was originally commissioned to run on the BBC Forces Programme for eight weeks but, excluding a break between 1946-51, has remained on air for 42 weeks a year ever since. Plomley himself presented the programme until his death in 1985, in which time he recorded 1,791 episodes. He was succeeded as presenter by Michael Parkinson.

Desert Island Discs still features the same theme music, “By the Sleepy Lagoon” by Eric Coates which is overlaid with sounds of herring gulls to conjure up the feeling of being by the sea. Some listeners, however, continue to take issue with this sound effect since herring gulls are not known to congregate near tropical islands.

On the 9th December 1965, American television network CBS first broadcast the animated cartoon A Charlie Brown Christmas. Now a staple of American Christmas television, the cartoon was originally financed by the Coca-Cola Company as a vehicle for Christmas advertising and was created in just six months.

By the mid-1960s, the Peanuts comic strip by American cartoonist Charles M. Schultz had become an international phenomenon. Ideas for an animated special had already been proposed, but it wasn’t until the influential Time magazine featured the Peanuts gang on the cover that sponsorship for the special was secured. Coca-Cola put up the money based on a simple pitch of “winter scenes, a school play, a scene to be read from the Bible, and a sound track combining jazz and traditional music.”

The creators took, at the time, a number of risks with the special. As well as exclusively casting children to voice the characters, Schultz opted for an unconventional jazz music soundtrack and refused to have a laugh track to accompany the animation. Combined with the necessarily simple animation and relatively slow pace, network executives expressed reservations about whether the special was even worthy of being shown.

However, having been completed just ten days before its network premiere the executives didn’t have much choice. They needn’t have worried, with popular and critical responses to the cartoon being universally positive. A Charlie Brown Christmas went on to win both a Peabody Award and the Emmy Award for Outstanding Children’s Program, but more importantly captured the imaginations of the 16 million people who tuned in to watch it that evening.

On the 23rd November 1963, the first ever episode of cult science fiction television show Doctor Who was broadcast by the BBC. Called An Unearthly Child, the episode was the first of a four-part serial that saw actor William Hartnell take the role of the time-travelling Doctor – a character he played for three years. The show was greeted with a generally positive reception, even though its launch was affected by a power cut in parts of the country as well as being significantly overshadowed by the assassination of John F. Kennedy the previous day.

Doctor Who was originally conceived to bridge the gap in the Saturday evening television schedule between the adult-oriented sports program Grandstand and the more teenage-focused music quiz Jukebox Jury. The idea of a time-traveling science fiction series appealed to Sydney Newman, the BBC’s new Head of Drama, who came up with the idea of a time machine that was bigger on the inside along with creating the mysterious character of “the Doctor”.

Produced by Verity Lambert and directed by Waris Hussein, An Unearthly Child was taped ‘as live’ on the 27th September. However Newman was unhappy with many elements such as technical problems and performance errors including fluffed lines, so a second version was taped on the 18th October.

The overshadowing of the episode’s first broadcast by the Kennedy assassination led to it being repeated directly before the second episode the following week which saw increased viewing figures. Popularity skyrocketed with the second serial – The Daleks – a storyline that was initially rejected due to it featuring so-called “bug-eyed monsters”.

On the 23rd September 1974, the world’s first teletext service went live when the BBC began transmitting its Ceefax service. Designed as a way to broadcast text-based information during the overnight ‘close-down’ of television services, it was the dominant medium for accessing breaking news until the arrival of the World Wide Web.

A system for broadcasting text had been developed by the BBC during the 1960s, but it was a noisy and limited mechanical system that only ever made it as far as internal tests. However, the advancement of digital technology in the early 1970s led to the emergence of a new system that was originally developed to encode subtitles to assist viewers who were deaf.

Launched slightly before the competing ORACLE system that had been developed by the Independent Broadcasting Authority, Ceefax made 30 pages of information available on its first day. However, this quickly grew to the point where hundreds of pages of up-to-the minute information were being shared. At times Ceefax pages were even broadcast as conventional television images in order to fill gaps between programming.

Within two years the creators of Ceefax and ORACLE had settled on a standard teletext system that became known as World System Teletext and was employed by a host of international broadcasters. However, the rapid rise of the internet and the arrival of digital television in the first decade of the 21st Century saw Ceefax and related teletext services become redundant as the information was available elsewhere. Ceefax itself was switched off shortly after 11.30pm on the evening of the 23rd October 2012.