The KLF (also known as The Justified Ancients of Mu Mu, furthermore known as The JAMs and The Timelords and by other names) were a British electronic band of the late 1980s and early 1990s. Beginning in 1987, Bill Drummond (alias King Boy D) and Jimmy Cauty (alias Rockman Rock) released hip hop-inspired and sample-heavy records as the Justified Ancients of Mu Mu, and on one occasion (the British number one hit single "Doctorin' the Tardis") as the Timelords. The KLF released a series of international hits on their own KLF Communications record label, and became the biggest-selling singles act in the world for 1991. The duo also published a book, The Manual (How to Have a Number One the Easy Way), and worked on a road movie called The White Room.

In 1986, Bill Drummond was an established figure within the British music industry, having co-founded Zoo Records, played guitar in the Liverpool band Big in Japan, and worked as manager of Echo & the Bunnymen and the Teardrop Explodes. On 21 July of that year, he resigned from his position as an A&R man at record label WEA, citing that he was nearly 33 1/3  years old (33 1/3  revolutions per minute being significant to Drummond as the speed at which a vinyl LP revolves), and that it was "time for a revolution in my life. There is a mountain to climb the hard way, and I want to see the world from the top". He released a well-received solo LP, The Man, judged by reviewers as "tastefully understated," a "touching if idiosyncratic biographical statement" encapsulating "his bizarrely sage ruminations", and "a work of humble genius: the best kind". Artist and musician Jimmy Cauty was, in 1986, the guitarist in the commercially unsuccessful three-piece Brilliant--an act that Drummond had signed to WEA Records and managed. Cauty and Drummond shared an interest in the esoteric conspiracy novels The Illuminatus! Trilogy and, in particular, their theme of Discordianism, a form of post-modern anarchism. As an art student in Liverpool, Drummond had been involved with the set design for the first stage production of The Illuminatus! Trilogy, a 12-hour performance which opened in Liverpool on 23 November 1976. Re-reading Illuminatus! in late 1986, and influenced by hip-hop, Drummond felt inspired to react against what he perceived to be the stagnant soundscape of popular music. Recalling that moment in a later radio interview, Drummond said that the plan came to him in an instant: he would form a hip-hop band with former colleague Jimmy Cauty, and they would be called the Justified Ancients of Mu Mu. It was New Year's Day ... 1987. I was at home with my parents, I was going for a walk in the morning, it was, like, bright blue sky, and I thought "I'm going to make a hip-hop record. Who can I make a hip-hop record with?". I wasn't brave enough to go and do it myself, 'cause, although I can play the guitar, and I can knock out a few things on the piano, I knew nothing, personally, about the technology. And, I thought, I knew [Jimmy], I knew he was a like spirit, we share similar tastes and backgrounds in music and things. So I phoned him up that day and said "Let's form a band called The Justified Ancients of Mu-Mu". And he knew exactly, to coin a phrase, "where I was coming from". And within a week we had recorded our first single which was called "All You Need Is Love". In 1988, Drummond and Cauty became "Time Boy" and "Lord Rock", and released a 'novelty' pop single, "Doctorin' the Tardis" as The Timelords. The song is predominantly a mash-up of the Doctor Who theme music, "Block Buster!" by Sweet and Gary Glitter's "Rock and Roll (Part Two)". Also credited on the record was "Ford Timelord", Cauty's 1968 Ford Galaxie American police car (claimed to have been used in the film Superman IV filmed in the UK). Drummond and Cauty declared that the car had spoken to them, giving its name as Ford Timelord, and advising the duo to become "The Timelords". Drummond and Cauty later portrayed the song as the result of a deliberate effort to write a number one hit single. In interviews with Snub TV and BBC Radio 1, Drummond said that the truth was that they had intended to make a house record using the Doctor Who theme. After Cauty had laid down a basic track, Drummond observed that their house idea wasn't working and what they actually had was a Glitter beat. Sensing the opportunity to make a commercial pop record they abandoned all notions of underground credibility and went instead for the lowest common denominator. According to the British music press, the result was "rancid", "pure, unadulterated agony" and "excruciating" and - in something of a backhanded compliment from the normally supportive Sounds Magazine - "a record so noxious that a top ten place can be its only destiny". They were right: the record went on to sell over one million copies. A single of The Timelords' remixes of the song was released: "Gary Joins The JAMs" featured original vocal contributions from Glitter himself, who also appeared on Top of the Pops to promote the song with The Timelords. The Timelords released one other product, a 1989 book called The Manual (How to Have a Number One the Easy Way), a step-by-step guide to achieving a number one hit single with little money or talent. The K Foundation was an arts foundation established by Drummond and Cauty in 1993 following their 'retirement' from the music industry. From 1993 to 1995 they engaged in a number of art projects and media campaigns, including the high-profile K Foundation art award (for the "worst artist of the year"). Most notoriously, they burnt what was left of their KLF earnings--a million pounds in cash--and filmed the performance. In 1995, Drummond and Cauty contributed a song to The Help Album as The One World Orchestra ("featuring The Massed Pipes and Drums of the Children's Free Revolutionary Volunteer Guards"). "The Magnificent" is a drum'n'bass version of the theme tune from The Magnificent Seven, with vocal samples from DJ Fleka of Serbian radio station B92: "Humans against killing... that sounds like a junkie against dope". On 17 September 1997, ten years after their debut album 1987, Drummond and Cauty re-emerged briefly as 2K. 2K made a one-off performance at London's Barbican Arts Centre with Mark Manning, Acid Brass, the Liverpool Dockers and Gimpo; a performance at which "Two elderly gentlemen, reeking of Dettol, caused havoc in their motorised wheelchairs. These old reprobates, bearing a grandfatherly resemblance to messrs Cauty and Drummond, claimed to have just been asked along." The song performed at the Barbican--"Fuck the Millennium" (a remix of "What Time Is Love?" featuring Acid Brass and incorporating elements of the hymn "Eternal Father, Strong to Save")--was also released as single. These activities were accompanied by the usual full page press adverts, this time asking readers "***k The Millennium: Yes/No?" with a telephone number provided for voting. At the same time, Drummond and Cauty were also K2 Plant Hire, with plans to build a "People's Pyramid" from used house bricks; this plan never reached fruition at the time. However, during the Welcome To The Dark Ages event in August 2017, Cauty and Drummond announced the creation of an undertakers business and new plans for a People's Pyramid. As of 2010, Drummond continues to work as a writer and conceptual artist, with occasional appearances on radio and television. Cauty has been involved in several post-KLF projects including the music and conceptual art collective Blacksmoke and, more recently, numerous creative projects with the aquarium and the L-13 Light Industrial Workshop based in Clerkenwell, London. CANNOTANSWER

did they really retire or was it for a short period?

From 1993 to 1995 they engaged in a number of art projects and media campaigns, including the high-profile K Foundation art award (for the "worst artist of the year").