Ozzy Osbourne reunited with his Black Sabbath bandmates for the first time in 20 years at their farewell show, Back to the Beginning, in Birmingham, England, on July 5

Sometimes it's easy to assume that all famous people know each other. But until Saturday's (July 5) Back to the Beginning blow-out final show honoring Ozzy Osbourne and Black Sabbath, the Prince of Darkness had never met Guns N' Roses singer Axl Ros e. Despite both men being hard rock royalty, their paths had somehow never crossed.