Writing and recording
Following the release of Led Zeppelin III in October 1970, the group took a break from live performances to concentrate on recording a follow-up. They turned down all touring offers, including a proposed New Year's Eve gig that would have been broadcast by television. They returned to Bron-Yr-Aur, a country house in Snowdonia, Wales, to write new material.
Recording sessions for the album began at Island Records' Basing Street Studios, London in December 1970. The group had considered Mick Jagger's home, Stargroves as a recording location, but decided it was too expensive. They subsequently moved the following month to Headley Grange, a country house in Hampshire, England, using the Rolling Stones Mobile Studio and engineer Andy Johns, with the Stones' Ian Stewart assisting. Johns had just worked on engineering Sticky Fingers and recommended the mobile studio. Guitarist and producer Jimmy Page later recalled: "We needed the sort of facilities where we could have a cup of tea and wander around the garden and go in and do what we had to do." This relaxed, atmospheric environment at Headley Grange also provided other advantages for the band, as they were able to capture spontaneous performances immediately, with some tracks arising from the communal jamming. Bassist and keyboardist John Paul Jones remembered there was no bar or leisure facilities, but this helped focus the group on the music without being distracted.
Once the basic tracks had been recorded, the band added overdubs at Island Studios in February. Page then took the completed master tapes to Sunset Sound in Los Angeles for mixing, on Johns' recommendation, with a plan for an April 1971 release. However, the band disliked the results, and so after touring through the spring and early summer, Page remixed the whole album in July. The album was delayed again over the choice of cover, whether it should be a double album, with a possible suggestion it could be issued as a set of EPs.