I think Orson Scott Card wrote "Speaker for the Dead" first and decided he needed another book just to set up the backstory. That book became Ender's Game, and

I think Orson Scott Card wrote "Speaker for the Dead" first and decided he needed another book just to set up the backstory. That book became Ender's Game, and he found it a bit ironic that he's remembered more for the prequel than the book he really felt compelled to write.