The "land of ice and snow" is Iceland, where the band played in June 1970. Robert Plant explained: "We weren't being pompous. We did come from the land of the ice and snow. We were guests of the Icelandic Government on a cultural mission. We were invited to play a concert in Reykjavik and the day before we arrived all the civil servants went on strike and the gig was going to be canceled. The university prepared a concert hall for us and it was phenomenal. The response from the kids was remarkable and we had a great time. 'Immigrant Song' was about that trip and it was the opening track on the album that was intended to be incredibly different."

One of the lyrics became part of Led Zeppelin lore. The line, "The hammer of the gods will drive our ships to new lands" got many of their fans referring to Zeppelin's sound as the "hammer of the gods." The phrase was used by author Stephen Davis as the title of a book about the band.

Led Zeppelin meant for this song to be somewhat humorous, relating their adventures on the road to the Vikings who fought the hordes to conquer new lands. They weren't known as a funny band, so a lot of their fans took it quite seriously.