Sydön (ᛋᛦᛐᚯᚿ), also known as the "South Island", is the second largest island of Teer. It is completely controlled by Tórviland in the modern day. While the island has many different biomes including mountains, grasslands, and forests; most of it is a swampy low-lying region known as the Eteläsuo Bog (ᛂᛏᛂᛚᛅᛋᚢᚮ).
Little is known about the exact history of Sydön, the southern island of Teer. The South Island has always been a wilderness full of hills, swamps, and bogs. Though it is nowadays considered to be a part of Teer culturally and geographically, before the Cometfall the kingdoms of northern Teer paid little to no attention to the South Island due to its perceived danger and hostility of its tribal chiefdoms in addition to the comparatively harsh and warmer climate.
What has always been true about the island post Beastbirth in BR810 is that it has been mostly populated by beastfolk. Cervans, Panshera, Saurians, Vulpines, Ursines, and Aven have long populated the island with the other species such as humans and elves always being in the minority. Most of these beastborn residents believe that the Beastbirth took place at Sydön, though it more likely happened across the sea in the Goldheim Rainforest.
Whatever the pre-written tribal history of Sydön island may have been, the first city-state petty kingdoms started forming after the Cometfall into the second era. Exposure to foreign technologies and cultures through trade between Eteru and Eqos forced the native beastfolk to modernize and adopt new ways. The largest of these tradeports was the city-kingdom of Hirvelä. However, these cities were all quickly conquered by the new High Kingdom of Jørdheim which sought to unify the continent. Sydön was primarily colonized by the former Jómagarðaríki's snow-elves who brought in much of their language, culture, and writing system into the island.
The locals of Sydön tried to reassert their power multiple times through the second era as well over centuries, though the combined might of the high kingdom—stretched thin as it was—proved difficult to overcome. However, post civil-war and the independence of Jómagarðaríki, the restored elven queendom got to keep Sydön though not for long. The elves alone were no longer able to maintain their hold on the island, and after a small war of independence the islanders separated to form their own kingdom. For the first time in its history, the entirety of Sydön island unified to become "Tórvi" or the Kingdom of Tórviland.