"Rover" is old British slang for a wanderer. The lyrics are fitting to this definition. (thanks, Mason - Greenville, NC)
This began life as an acoustic piece. Jimmy Page and Robert Plant started writing it in 1970 at Bron-yr-Aur, the cottage in Wales they went to after a brutal US tour. The cottage had no electricity or running water.
Led Zeppelin recorded this at the Houses Of The Holy sessions. They didn't use it on that album, so they remixed it for Physical Graffiti.
Led Zeppelin never played this live, but during their 1977 tour of the United States, the band would often use the opening riff to segue into "Sick Again." (thanks, Chris - Whitesboro, NY)
The intro is very close to the Kinks track "Wicked Annabella" from their Village Green album. (thanks, John - Waterford, Ireland)
