The Xertavi Dynasty lasted an unknown time period as no written records were ever found. Which makes sense as the lichs never died and didn’t need to write anything down. What is known is that 22 individual lichs came from the under-dark of Sarnath and ruled the land oppressively through sorcery and sword. Until recently it was assumed that they actually created the sentient races of Thanatops to serve them as slaves. This explained their ability to manipulate flesh and bone, life and death. They appeared similar to elves but had dark, obsidian black skin and the females were notably larger then the males. All of the current cities accept New Sarnath were originally built by the Lichs design, though they bore diffrent names.