Songfacts®:

• "Children of the Sea" is perhaps the most distinctive song from the Black Sabbath album Heaven and Hell. While the writing credits on the album are given to the entire crew of Ronnie James Dio, Tony Iommi, Bill Ward and Geezer Butler, the rest of the group already had the tune while Dio, brought in to replace Ozzy Osbourne, wrote the lyrics.
  
  In the book Precious Metal: Decibel Presents the Stories Behind 25 Extreme Metal Masterpieces, Dio tells how this song became his welcome to the band: "I met them at the house that they were using to rehearse in and purely went to say hello and get to know them. I had no thoughts whatsoever of being in the band. As far as I knew, Ozzy was still in the band. During the conversation, Tony asked me if I'd like to see the studio they were doing their things in. He, Geezer and Bill picked up their instruments and started to play [what became] 'Children of the Sea' and I liked it very much. Tony asked me if I could do anything with it. I said, 'Give me a few minutes, I think I can knock something out.' We pretty well wrote the song that quickly."
  
  Incidentally, in the aforementioned book it is revealed that this was almost the end of Black Sabbath! The band had agreed that if any of the seminal members left, they wouldn't call whatever remained "Black Sabbath" any more. What saved the name? They were contractually obligated to produce one more album with Vertigo/ Warner Brothers!
• "Children of the Sea" is one of the most enigmatic Black Sabbath songs as far as lyrics go. On the matter of Dio's lyrics - a marked change from Ozzy's - we have only some quotes from Precious Metal:
  
  Dio: "I was never questioned about what I was going to write or what I did write. I questioned it more than they."
  
  Butler: "He took [the lyrics] more in the fantasy theme. It stayed on that same sort of mystical theme. I always liked listening to Ronnie's lyrics. They were so different from what I could do."
  
  Ward: "For me, there were some lyrics that were absolutely brilliant, and there were some lyrics that, kind of like, 'Oh, I can't believe I'm participating in that.'"
  
  By the way, Dio's actual birth name is Ronald James Padavona, and he was born to an Italian family in Portsmouth, New Hampshire. "Dio" is the Italian word for "God." Nevertheless, Dio has mentioned in interviews with HM Magazine that he was at odds with his Catholic upbringing, although he doesn't give the idea of being "anti-Christian" much thought, either.
• No relation is evident between this song and the (beginning 2007) manga series of the same title.
• The song was originally recorded with an entirely different vocal melody and lyrics by original Black Sabbath vocalist Ozzy Osbourne prior to his ousting.
• Sabbath guitarist Tony Iommi wanted the song to evoke "a giant ship rowed by galley slaves."