The environmental movement was just getting started in 1971 when Black Sabbath released "Children Of The Grave," a stark warning about what could happen if we continue to neglect the earth and destroy each other. Geezer Butler, the bass player in the band, wrote the lyric, as he did on most Sabbath songs at this time. He explained the meaning in a Songfacts interview: "People were just starting to realize about pollution. Climate change and that sort of stuff. It was right at the beginning of that, and it was a song about how we are all going to be children of the grave if we don't do something about the environment."

"Children Of The Grave" is one of Black Sabbath's most popular songs. It has all the ingredients of Sabbath goodness: Beastly drumming by Bill Ward, the mighty guitar of Tony Iommi, and an incisive lyric by Geezer Butler delivered with conviction by Ozzy Osbourne. The song was a regular part of their live shows even when Ronnie James Dio took over as lead singer. When Ozzy went solo, he often included it in his setlists as well.

The song is from the third Black Sabbath album, Master Of Reality. They were defining "heavy metal" around this time thanks to songs like this one. And they were extremely productive - their first two albums were both released in 1970, and they followed with new albums in 1971, 1972 and 1973. At first, the band didn't get much airplay and even less respect from the music press, but by the time Master Of Reality was issued they had won over many critics and built quite a following. They started to unravel creatively and personally starting with their 1975 album Sabotage. In 1979, Ozzy was ejected from the band, replaced by Ronnie James Dio.