As heavy metal steadily approaches 50 years of existence, it's flooring to look at how the genre has evolved since Black Sabbath released their debut album on Feb. 13 of 1970. Oh, and if you're wondering, yes, it was the ominous Friday the 13th.

While the Birmingham, England, group owned this new style, then dubbed 'downer rock,' it eventually caught fire at the tail of the decade (with the help of Judas Priest), smashing down the door as the decade turned over, owning the next 10 years with the emergence of the New Wave of British Heavy Metal, the first wave of black metal, thrash and death metal's infancy.

The next decade, the 1990s, saw metal fall by the wayside in terms of commerciality, save for Pantera, who implemented a powerful new style, honing in on groove and a dominant lyrical style. It was also the most popular decade for the second wave of black metal and death metal, which began branching off into different factions (brutal, technical, progressive) quite early on.

The stylistic door was shattered with the arrival of the new millennium as melding genres became commonplace and metal furthered its descent into a never-ending well of subgenres and frustrated categorization. Technical prowess was generally the benchmark by which bands began to be judged as evident by our selections.

Sorting through all of the top albums of each year from nearly five decades of music was a chore (a welcome one) and after endless discussion we came away with what you see in the Best Metal Album of Each Year Since 1970 gallery at the top of the page! Take a look through the best metal has had to offer year by year!

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