On this page we look at presentation on the digital-only channel BBC4, along with its predecessor BBC Knowledge. Click here for a look in greater detail at the story of BBC digital television.
We also have pages looking at idents from BBC1, BBC2, BBC3/Choice, CBBC and UKTV, and regional ITV idents. If you want to explore the subject of television presentation in greater depth, see our links page for related sites.
The BBC's interactive learning channel, BBC Knowledge, launched on 1st June 1999. Click here for a look at the channel's programming over its lifetime.
The channel was initially aimed at both children and adults, with a bright and brash approach to education. This was reflected by these three cartoonish idents - 'Magnify', 'Propeller', 'Designer'.
The original BBC Knowledge format was dumped overnight on 3rd April 2000, and it instead began to transform into a serious documentary and arts channel. Each weekday now had a specific theme, and new themed idents were introduced for history (Mondays), science (Tuesdays) and arts (Fridays) - but not for business (Wednesdays) or languages, film and culture (Thursdays), when the original 'Magnify' ident continued to be used. It was also used on Saturdays and Sundays, which had no specific theme. Themed idents for Wednesdays and Thursdays were introduced around July 2000, when the now incongruous 'Magnify' was dropped.
Then, just before Christmas 2000, a new ident was introduced. Initially it was used to precede the themed idents, but this format was dropped early in 2001. This single ident, which repeats ad infinitum, continued in use until the channel was replaced by BBC4 in 2002.
The BBC's new channel promising a 'feast of culture' launched on 2nd March 2002. BBC4 may well have been able to claim a world first with its idents - rather than existing as recorded sequences, the animations were created live on air by a specially designed computer system. These images reacted to a randomly chosen instrumental theme, and even to the announcer's voice - so you never saw the same sequence twice!
Click here for more idents from this era.
After three-and-a-half years of random shapes, the BBC4 bosses decided it was time for a change, and a new ident package launched on 10th September 2005. The idents are based around optical illusions, where what appears at first to be a single everyday image is in fact made up of four separate frames.
These idents would prove unexpectedly long-lasted, with two of the original six variants ('Lake' and 'Flowers') still on air well over a decade later.
In 2016 they were joined by some new additions, shown here.
From our YouTube channel, some BBC Knowledge idents, the closure of BBC Knowledge and launch of BBC4, and BBC4 idents introduced in 2002 and 2005.