Following their eponymous debut album and their million-selling Paranoid, both released in 1970, Black Sabbath returned to Island Studios in London just months later, in February and April 1971, to record their third album. The album was produced by Rodger Bain, who had also been involved in the two previous albums. Master Of Reality was released in July 1971 on Vertigo and was an immediate huge success. Their experimental approach of tuning the guitars lower created a much harder and more threatening sound than on their two previous heavy metal albums. This resulted in their most influential work sonically and played a major role in the development of sludge, stoner and doom metal. By the way, the coughing at the beginning of Sweet Leaf came from Tony Iommi shortly after he had taken a hit on a joint.

For many, this album is a seminal album in the history of rock music and one of the most important albums of all time. Demand is correspondingly high, especially for the English first edition, which was released in a box sleeve with a flap at the top, containing a poster of the band (photographed by Keef) and featuring the album title in embossed lettering.