British band whose bludgeoning brand of rock defined the term heavy metal in the 1970s. The principal members were Ozzy Osbourne (Osbourne, Ozzy) (byname of John Osbourne; b. Dec. 3, 1948, Birmingham, Warwickshire, Eng.), Terry (“Geezer”) Butler (b. July 17, 1949, Birmingham), Tony Iommi (b. Feb. 19, 1948, Birmingham), and Bill Ward (b. May 5, 1948, Birmingham).

Osbourne, Butler, Iommi, and Ward, schoolmates in Birmingham in the late 1960s, formed the blues bands Polka Tulk and Earth. These evolved into Black Sabbath, which was named after a Butler song inspired by a Boris Karloff (Karloff, Boris) movie. The band cultivated a dark and foreboding image with ominous guitar riffs, slow-churn tempos, and Osbourne's sullen vocals. Black Sabbath's lyrics, soaked in occult imagery, and coarse musicianship were reviled by critics and shunned by radio programmers, but constant touring turned them into stars, and songs such as “Paranoid,” “Iron Man,” and “War Pigs” became metal classics. By the end of the 1970s they had sold millions of records and had become the standard by which virtually every heavy metal band had to measure itself. Osbourne left the band in the late 1970s, and Ward and Butler later followed him out. Iommi kept the Black Sabbath name alive throughout the 1980s with a variety of musicians, and Osbourne forged a solo career marked by outrageous drug-fueled antics, best-selling albums, and the hugely popular MTV reality show The Osbournes (2002–05), which followed Osbourne and his family. In the 1990s the original lineup reunited on several occasions. Black Sabbath was inducted into the Rock and Roll Hall of Fame in 2006.