Supreme Throne

The Supreme Throne, also known as the Shattered Keep, the Shattered Castle, and the Castle of the Supreme Throne, was the divine realm of Cyric, the Prince of Lies, after he relocated from his previous realm of Bone Castle in Hades. Following the murder of the Goddess of Magic, Mystra, the realm also became Cyric's prison, by the hands of fellow gods Lathander, Tyr, and Sune.

Cosmology
According to the Great Wheel cosmology, the Supreme Throne was a realm in Cocytus, the second layer of Pandemonium. In the World Tree cosmology, it was a fiendish plane. In the World Axis cosmology, it was considered an astral dominion.

Geography
Much like the rest of Cocytus, the Supreme Throne was a barren realm where howling winds could drive mortals mad. Because Cyric was the enemy of all other faiths, the followers of any deity besides Cyric found their spells more difficult to cast on the plane.

The name "Shattered Castle" was used in the World Tree cosmology to refer to the realm's only standing structure, a ruined fortress that first served as Cyric's seat of power, and as his prison afterwards.

History
According to a thrall captured by mind flayers of Oryndoll beneath Andalbruin, the Supreme Throne was originally established in the plane of Limbo by batrachi who had left Toril after around −30000 DR. There, the deity called Ramenos once again changed the batrachi to serve his goals.

The Shattered Castle was then moved by Cyric and brought to Pandemonium as he retreated to that plane after reading the Cyrinishad. Cyric, driven mad, abandoned Bone Castle in Hades and established his new realm in Cocytus as a twisted, ever-changing fortress, which served as his base from where he hatched his plans to conquer Toril.

In the, after Cyric murdered Mystra and triggered the Spellplague, Lathander, Sune, and Tyr decreed that Cyric be imprisoned in the Supreme Throne for 1000 years.

Inhabitants
The Supreme Throne was the home plane of chaos beasts, demodands, howlers, and slaadi. It was also inhabited by batrachi. Among them was Bazim-Gorag, the Firebringer.

Rumors & Legends
A rumor existed that seven black iron keys were required to free Cyric from his shackles within his prison.