Appears In: BoD, DRC Research
The Age of Terahnee is at least as old as the Age of Earth, in terms of when the link was established. The majority of the Ronay, upon discovering that their home world of Garternay was going to collapse, evacuated to Terahnee, and took on the name of the Age as their own (much as the D'ni people took on the name of the Cavern, which is also called D'ni). The name terahnee means "the new tree", playing on the fact that their homeworld's name, Garternay, means "root of the tree".
The Age itself is massive. Huge expanses of land stretch from horizon to horizon. Clearly Terahnee was written as a homeland for a very large number of people (the count given in Book of D'ni is 200 million). This land is dotted with huge mansions of local landowners and governors, and criss-crossed with canals, along which boats glide seemingly effortlessly. The capital of Terahnee is described as being a huge man-made mountain which would have dwarfed all of D'ni. The tower of the King's chamber alone was more than a mile above the rest of the city, which continued downwards for miles upon miles below that point.
Following the fall of the Terahnee people, the land was claimed by the Relyimah slaves who had survived the plague that swept the land, eradicating nearly all of the Terahnee. Even though a great many Relyimah fell victim to the same plague, they still numbered over 2 billion. These people took upon themselves the re-shaping of the land for their own needs, using the houses as local government headquarters and even re-naming the Age Devokan, the D'ni word for hope.