Inteper Isle was first settled in -3840 AR by Kellids from Druma seeking to escape famine and the rule of the dwarves of Tar Taargadth. Under the rule of charismatic leaders and the Speakers of the Pale, by -2301 AR, the various fishing villages on Inteper Isle united into a kingdom with its capital at the city of Kestrillon. In -355 AR, Kestrillon ceded its autonomy to Sarkoris after generations of threats and skirmishes.

Kestrillon later became the refuge of the Golden Solidarity, a fringe sect of the Prophecies of Kalistrade. Their wealth attracted the attention of Tar-Baphon, who, in 861 AR, invaded Inteper Isle with an undead army, slaughtered Kestrillon's people, turned them into undead, and renamed Kestrillon to Xin-Grafar, after the Thassilonian style.

In 872 AR, Tar-Baphon discovered a strange thinness between the planes on the Isle of Terror. After taking over the whole island from the black dragon Karamorros in 881 AR, he exploited it to dig the Wizard-King's Pit, a portal to the Void. With the island secure, he stored his wealth in Xin-Grafar, filling it with deadly traps and guardians. His ultimate plan was to entrap Aroden within his new city and destroy him utterly.

In 896 AR, Aroden confronted Tar-Baphon on the Isle of Terror. The necromancer had created a magical trap there for the Last Azlanti, located in an immense shaft known as the Well of Sorrows within the Wizard-King's Pit. Tar-Baphon lost the fight, and his corpse was buried by Aroden on the Isle of Terror, until his followers reburied him in his homeland of Ustalav a year later.

In recent years, the isle was racked by continuous storms (natural and otherwise) and was evaded by all but the most foolhardy of travelers. Monsters and undead roamed the island and the seas churned constantly around it, driven by powerful winds and pounding rain. Stories persisted of especially brave or foolhardy pirates who braved the elements and the Isle of Terror's shore in order to hurriedly hide treasure somewhere on the land before quickly escaping. Some sailors reported sightings of a rotten ship with tattered black sails, the Nixie's Pride, near the blighted island during a new moon.9

The Isle of Terror's rocky shore provided few berths for ships to land. Perhaps the safest place to make landing was on the west coast in a small half-moon bay known as Aroden's Landing. This is the site of the ruins of Fort Landing, which stand at the mouth of the Whispering River and mark the road to Xin-Grafar, although only a fool would have considered any location truly safe. The Whispering River flows from the Three Furies at the island's heart, under which are the Wizard-King's Pit and the Well of Sorrows, which have remained active since Tar-Baphon created them to trap Aroden.