Negletic was originally known as Seashalia by the native populations who lived on the continent. The original continent was home to exclusively elf and fae populations. Humans, dwarves, halflings, etc. did not live on Seashalia and would only later be introduced to the continent through colonialism.
There was one main “border” on Seashalia, that being the small pass in current-day Vusnuicor. Everything to the west was primarily Elven territory and everything to the East was primarily Fae territory. However, it was not a hard border. While many families primarily came from and ultimately settled in their respective territories, both populations could freely visit either side of the continent and settle wherever they pleased. Towns were made and groups created anywhere in the continent without much issue beyond family spats.
There is not much recorded about Seashalia’s time before colonialism. There are some stories shared in Elven circles that talk about the times in old Seashalia, but most of that is told purely through oral tradition, with not many elves choosing to write it down, and so there is not much known to wider audiences about what Seashalia was like before it was renamed to Negletis.