The War Between Tritons and Aboleth

Centuries ago, tritons entered the world in response to the theft of the dragonforging artifacts. Like the Kraken, they were tasked with preventing the chromatic dragons from passing through the Elemental Waygate.
They soon discovered another enemy. Curious about these new arrivals in the ocean, the aboleth enslaved several triton. Intrigued and delighted by their new slaves' tales of the Plane of Water, a world entirely consisting of the aboleth's favorite habitat, they plotted to conquer this new plane. With the help of their slaves, they snuck several through the Elemental Waygate before getting caught, resulting in a fierce battle.
At first, the tritons hoped they'd stopped the aboleth from getting through, but they soon learned their hopes were in vain. Although cut off from their fellows, a few aboleth had escaped into the Plane of Water and begun forming hidden strongholds in the Darkened Depths where they escaped into the crushing pressure and utter darkness. As far as the triton know, they dwell in these depths to this day.
Now fighting the aboleth on two fronts, the tritons spread across the world's oceans and established protectorates to watch over deep sea trenches, portals, undersea caves, and other locations where their enemies might lurk. They defeated their foes when they could and drove them into hiding. With their foes banished to the deepest reaches of the sea, tritons settled in to watch for any sign of their return. Over time, the tritons extended their stewardship over the sea floor from their initial settlements and built outposts to create trade with other races. Despite this expansion, few folk know of them. Their settlements are so remote even sea elves rarely encounter them.