The Fall of Shanti

You don't need to play "Heroes of Might and Magic VI" to know that there's a Naga faction there. ;)

I'll clarify right away that in studying the setting, I rely on this article.

If we assume that the Empire of Shantiri is a union of all the Ancient races, then after the empire's collapse, although many representatives of the races survived, they ceased to be Shantirians.

I won't argue about the First Eclipse, but if the peoples had united every time, the Falcon Empire wouldn't have been destroyed during the Fourth Eclipse.