Fourteenth Century Sky is an EP by English big beat duo The Chemical Brothers, their second release under the name The Dust Brothers. The EP contains "Chemical Beats" and "One Too Many Mornings", later released on the Brothers' debut album Exit Planet Dust.
"One Too Many Mornings" found fame in 2001 after appearing on several chillout compilation albums. The version of "Chemical Beats" is the full-length version, with an extended intro. The full version of the song wasn't included on Exit Planet Dust due to an uncleared vocal sample and has not been available since. The sample was "take this, brother, may it serve you well," from The Beatles' song "Revolution 9". They were later miscredited as sampling The Beatles song "Tomorrow Never Knows" (which sometimes closed Chemical Brothers DJ sets) in their hits "Setting Sun" and "Let Forever Be" (both feature Noel Gallagher, a well acknowledged Beatles fan). to the point where they were almost sued. The Chemical Brothers and Virgin Records proved they did not sample the song. "Chemical Beats" later gave the duo their name The Chemical Brothers.
Another EP, My Mercury Mouth EP, is often believed to have been released the same day. In fact, it came later in 1994.