The Kingdom of Tethyr is the largest in the world and spans the entire continent. Once 5 different kingdoms, the kingdoms where united many generations ago to form 1 large kingdom with 5 Nation-States. Faerun, Elient, Alibeno, Edolas, and Dothrac.
The Kingdom is ruled over by King Gadrin Steelrun and his wife Queen Cersi. They have two sons, Crown Prince Edrador and Prince Myles. King Gadrin in his youth was a proud, strong warrior and hunter but over time, has become more interested in drinking, and chasing after women. This has caused distrust in many subjects and it seems the Nation-States are acting more independently as of late. Crown Prince Edrador is the first in 4 generations of Royal Steelrun to possess a natural ability for magic. As such, he travels the kingdom looking for ways to become a stronger Sorcerer in order to prove he is worthy of taking the throne.
There are several smaller islands that surround Tethyr that are considered sovereign and hold their own governments, such as Crab Island, The Tideless Chain, and Canmount Isles.