Tetri, more than even Gerel, is incredibly influenced by the race who calls it home. The Elves have molded and shaped it into their kingdom; they just allow others to live there. That isn't to say they're not welcoming, but there's an arrogance about the whole kingdom that is hard not to notice.
The land being postioned to the East, is one of flowing rivers and temperate forests. There are hills and something some might call mountains, but mostly Tetri is best known as "The Land of Rivers", with it's name meaining "river" in Elvish.
Because of it's geography, Tetri is a major hub for travel and shipping, with the Tetri government opperating the largest (and most powerful) Navy of all the Five Kingdoms.
The capital city of Tetri, Nytath Thalor (or just "Thalor" to non-elves) is a golden city built out into the ocean. It is a marvel of engineering, and despite what the Tetri government would tell you, the foundations of the city were built by Dwarves millenia ago, long before the two races had their falling out. The city has expanded in the interum, and the new additions are built to the same exacting precision as the original city, making it nearly impossible to tell what is old and what is new.
Tetri has a complicated history. Before the other Kingdoms were founded, a group of Humans, Dwarves, and Elves lived along the rivers, calling themselves "Dyath ly Tetri", or "The People of the River". They lived and worked in harmony, and over time their settlements along the rivers started to turn into cities. At the same time, the People of the River were learning to sail the ocean, fishing farther and farther from the river's mouth. Nytath Thalor was constructed to be a simple shelter for fishermen, so they didn't have to bring their boats up the river, instead being able to dock, resupply, and head back out.
It wasn't until after the founding of Kalisha that Tetri was formed as a government. And when it was, the fishing town that had been Nytath Thalor was torn down and in it's place the work of art that is the capital was built. Somewhere along the line, however, Dwarves and Elves went from working together to distrusting each other. There are now almost no Dwarves who live in Tetri, despite them being one of the founding races of the kingdom.
The government of Tetri is run by the Elves, and there is no room for debate on that subject. In fact, there is almost no transparency on the subject at all. The official description of their government, as stated by King Lialamin, is as follows:
"An Elf is King. Should that Elf no longer be able to rule, for whatever reason, a new King is chosen. Who the new King will be is obvious and the choice is —and always will be— unanimous. Other positions in the government are apointed as the King sees need. This system as worked for millenia, and will continue to work for as long as is required."
It should be noted that while there have been Elven Queens, no Queen has ever ruled on her own; she has always married as part of taking the throne. It is unknown why this is, as female Elves are allowed power at all levels of the government, and culturally there does not seem to be any obvious gender biases.
King Lialamin is, by all accounts, a very mild king. He has typical elven arrogance, but his policies have been forgetable, and in the last hundred years of rule, he hasn't done much of note, which is itself, notable.