The Lost Dales
Bards tell colorful tales of dales that are no more - overgrown ruins deep in the forest, their treasures waiting to be found. Much of this talk of dancing ghosts, stalking monsters, and lost riches is poetic fancy, but kernels of truth exist in every story. All folk know the names of the dales lost most recently: Moondale, Sessrendale, and Teshendale. Dales have fallen before, and dales will fall again.
Moondale: Far from the great forest and too close to Sembia, Moondale abandoned the Dalelands and joined the young merchant kingdom hundreds of years ago. Ordulin, Sembia's capital was built on the site of old Moondale. Dalesfolk take Moondale's transformation as a warning against growing too close to the power to the south. Tasseldarrans are the exception; some viewing Moondale's history as a plan instead of a warning.
Sessrendale: Sessrendale, the "Dead Dale," was founded 880 DR. It lay between the eastern face of the Thunder Peaks a westernmost verge of Semberholme, from Thunder Gap south to Tilver's Gap in the north. The southern half lay close Archendale, which also claimed Thunder Gap, and that sealed Sessrendale's doom.
A land of shepherds, masons, traders, and miners, Sessrendale was ruled by a Dusk Lord who was accused by Archendale of fell sorceries. The Dusk lord fell when Archendale's army invaded 1232 DR. The Archenfolk slew or drove off Sessrendale's citizens and destroyed all its buildings, fields, and mines. Then the Archenfolk sowed Sessrendale's fields with salt to ensure that Sessrenfolk families that had fled to Battledale and Deepingdale would never resettle their lands. Only a few trappers and woodcutters venture into haunted Sessrendale now.
Teshendale: Teshendale occupied the lands along the Tesh, within the shadow of Zhentil Keep. As Zhentil Keep transformed from an independent trading city into a hive of evil, Teshendale's days became numbered. Daggerdale has survived its bouts with Zhentil Keep relatively intact, but Teshendale succumbed to orc hordes recruited by the Zhents in 1316 DR. Teshwave and Snowmantle, former Teshendale towns, still figure in the Zhents' plans for the Dales.
The Dales Council keeps a seat open for the elder who used represent Teshendale, partially as a reminder of what happens those who underestimate the Zhents, and partially as a reminder that the Dales do not always manage to support each other quickly as they ought.