 EMI delayed the release of the album in the UK to June 1969, after the band had come back from the US and set up a proper tour of their home country. By that time, the band had already recorded and released their third album Deep Purple in the US, and recorded a single with a new line-up. The Book of Taliesyn was the first release by Harvest Records, a new sub-label which EMI executives had devised as an outlet for British underground progressive rock groups. "Kentucky Woman", with "Wring That Neck" as B-side, was the only single released in the UK in December 1969, but it was retired after only six weeks. Just as it had happened with Shades of Deep Purple the year before, both album and single received little promotion and were widely overlooked, selling much less in the UK than overseas.
