Venture Though Tamriel
Summerset Isle (sometimes spelled Sumurset Isle or Sumerset Isle, and known by the second Aldmeri Dominion as Alinor) is a large island to the southwest of Tamriel’s mainland. The Summerset Isles encompass a second, smaller island. In addition, it once contained the island system of Pyandonea, who seceded after a war with the King of Summerset. Summerset Isle is inhabited by the Altmer (called High Elves by Imperials), of whom magic is said to flow through their very veins. While the Sload are believed to be the first inhabitants of the Isles, it is believed to be the first province occupied by the Aldmer.
During the Oblivion Crisis, Summerset Isle was beset by daedra. The Crystal Tower was toppled by the daedra hordes. The Thalmor, once a minority voice, were given greater power and authority in order to deal with the crisis. They were successful and came to be seen as the saviors of Summerset Isle. In 4E 22, the Thalmor took control of the Summerset Isles and renamed them Alinor. Valenwood was brought under the Thalmor’s control in 4E 29, recreating the Aldmeri Dominion. Later, the former Confederacy of Elsweyr joined the Dominion as two separate client states.