Was Avatar the Last Airbender the first series to incorporate the elements into tribes/territories?

I just want to know if Avatar the last airbender was the first one to make tribes/territories out of the elements. I was suddenly inspired to write a novel where there are different kingdoms for certain elements and an heir to one of the kingdoms finds a person from another kingdom hiding out around her territory. Basically, I want to write a romance novel but I don't want it to seem like I'm copying avatar. Are there other books/ movies/ TV shows that used the elements in that manner? Also, I'd place mine where there were castles and towns instead of tribes, but I still don't know if it's original enough. I'd appreciate anyone's answers. Thanks!