Hoomans were not the first people to inhabit the lands currently and formerly inhabiting /who/. There was another population, one native to the territory. Hoomans and these native people were unwilling to coexist, thus starting what became known as the Founding War. Details of both the War and of the non-Hooman belligerents were often rendered incomplete due to both the volatile nature of affairs at the time and an effort after the fact to consolidate a common cultural and religious identity in /who/ after the fact, creating an air of mystery and mythology not only to the war but also to the non-Hoomans who were wiped out. The curiosity around what would become known as "they who were here before"* increased after the dissolution of the Owl Republic, with more than a few Hoomans looking through suspected former settlements and ancient documents that wrote from or of the time in an attempt to paint a picture of what this mysterious people was like.
The soft consensus around "they who were there before is that "they" were a people who lived primarily by the seaside but did venture inland along rivers to some extent. "They" were likely shorter and stockier than Hoomans to some extent and were almost certainly skilled in water-based travel to some extent. The latter in conjunction with their habitation patterns has led to speculation that "they" were anthropomorphic to some extent, with non-human elements of some form of marine life similar to the owl-like features found among Hoomans.
It is not known for certain, but it is widely assumed that "they who were here before" worshipped a Goddess of their own that was independent of any pantheon. Anthropologists who believe these people weren't entirely human likewise suggest they shared their animal traits with this Goddess. There has been speculation that this Goddess may have been the Pink One's past and that Hoomanity's past rejection of her in favor of maintaining their faith in the Nameless One led to the Pink One's repeated refusals to seek divinity even after the apothnitosis. More information can be found in "Catalog of Miscellaneous Otherworldly Entities"** which can be found in every official /who/ library.
As for the fate of "they who were here before", it is generally agreed upon by Hoomanity that they were ultimately driven to the Sea in the end of the Founding War and their cities and other settlements were destroyed along with any depiction of their Goddess for the reasons stated earlier. What became of "they" afterward is uncertain and a subject of speculation, with quite a few hypotheses having their shares of hoots vouching for them. Though the speculation itself is widely varied, a common assumption among them is that even with the Nameless One's loss of divinity, "they who were here before" will not return seeking revenge.
__________
*The quotation marks around any and all mentions of "they who were here before" will be replaced by italics in the rentry.
**I do intend to make a rentry with that title, and it will be linked when I have the free time (likely tomorrow).
Pic isn't directly related to the article, I just felt it would be good to break up the wall of text with something. If anything, it's the equivalent of a "Keep Calm and Carry On"-esque propaganda poster one may find during the Founding War. There is an image or two that fits better with the final paragraph, but putting it in this post would go against what I'm trying to go for as a rep as it shows someone I said I wouldn't directly depict unless I could pass it off as someone else.
This will be going into /who/'s history rentry (sans image). Credits to
>>108029239 for helping to clarify a geological matter. The specific locations don't matter too much, it's just good to know that such rivers could naturally exist. Thank you!