Chiaroscuro: Chronicles of the High Kingdom
The last, and longest, known major crossing of the shadar-kai into The True World. Centered in what later became the Barony of Eirnain in the The High Kingdom of Cymria, the Long Crossing lasted roughly 75 years, and reshaped much of the society of the Six Kingdoms.
The Long Crossing ended when the shadar-kai were cast out of the True World by an alliance of soldiers from the Six Kingdoms and dwarves from the citadels beyond the Highland Wall. The ritual of the Great Flame sealed closed the crossing points into Adumbra, theoretically forever, and thrust Cymria into the Warring States Period of the the modern era.