Book excerpt: A chronological review of the most essential and heaviest metal and hard rock albums, illustrated throughout, demonstrating the global popularity of the genre and just how much it has grown. The 1970s was the era when the great heavy metal pioneers laid down the blueprint for everything that was to come after, forefathers like Black Sabbath and Deep Purple dominated. But as metal began to take hold in the mainstream - and then began to diversify - bands such as Judas Priest, Iron Maiden, Metallica and Mötley Crüe made their presence felt among new fans, and it continues to evolve today with bands like Mastodon and Lamb of God. Providing an extensive overview of the music and the stories behind each album, this inclusive reference chronicles the history and development of heavy metal, including sub-movements such as death metal, speed metal, grindcore, and hair metal, illustrated with the iconic covers and archive photographs.