Board Thread:Lore Discussion/@comment-24344819-20140302100635/@comment-25047024-20140302145158

Neloth is a Telvanni. Telvanni are known to use magic to prolong their lifespan. So, it's possible that he's 2000-3000 years old. Although he's most likely not older than Divayth Fyr who was at the time of Morrowind 4000 years old.