A Fire Emblem game was in development for the Nintendo 64DD add-on; A CD drive add on for the cartridge based system. Nintendo, however decided that the 64DD would not sell and gave it a limited release in Japan before both the 64DD and it's games were canceled, or moved to the Nintendo 64 for a cartridge release.
After Fire Emblem 64 was cancelled, work began on a new Gameboy Advance title originally titled Fire Emblem: Ankoku no Miko (Maiden of the Darkness) which eventually became Fire Emblem: The Sealed Sword.
The original creator of Fire Emblem left Intelligent Systems and Nintendo after FE64 was cencelled and formed his own develement studio, Tirnanog.
Below are a few screenshots of a very early build of Path of Radiance, which seems to have a N64 quality to them which may have re-used assets from the canceled N64 game.