阿勒瑟拉（Alethela） was one of the Silver Kingdoms on Roshar. As one of the Silver Kingdoms, its name is perfectly symmetrical, due to the Vorin belief in holiness of symmetry.
When Urithiru was built, many people wanted it to be built in Alethela, but there was some unknown yet obvious reason why it could not be.
Although the orders of Knights Radiant were centered in Urithiru, Alethela was their home, and Radiants lived in cities throughout the nation, crossing borders to fight. Alethela was considered to be dedicated to the arts of war so that no other kingdom had to do so. They consider it their duty to protect all the other nations. People went to Alethela if they could fight or wanted to be trained. Those who had fought the Ten Deaths could go to Alethela and be trained so that the changes wrought in them by fighting the Ten Deaths would not destroy them.
By the time of the Era of Solitude, it had become the kingdom of Alethkar. During this transition, Alethela lost territory in the west to Jah Keved, but gained some in the north from Rishir, and in the southeast from Natanatan. Territory was also lost in the northeast, known in the Era of Solitude as the Unclaimed Hills.