Once the capital of the Kellid Kingdom of Sarkoris, the city long served as the headquarters of the Abyssal forces occupying Golarion. Other demon princes sent emissaries to the various "embassies" there, in the hopes of advancing their devious causes. When the Worldwound opened, Iz was located a full-day's ride southwest of the tear in reality.2 Despite the Worldwound's expansions that threatened Iz with windstorms and earthquakes, the city avoided totally falling into the Worldwound, though two-thirds of the city collapsed into the Worldwound itself when the rift first opened.3
Being primarily a habitat for demons, Iz had no real government in the traditional sense. Much like the other major cities of the region, it did have a single dominant figure whose desires were not contradicted: the powerful balor Khorramzadeh, also known as the Storm King.23
Iz is close to numerous metal-producing mines and was the metalworking centre of Sarkoris. This tradition continued throughout the demonic occupation, although the mine workers suffered under the whips of demonic overseers and broke all previous production records.23
The expansion of the nearby rift to the Outer Rifts led to the entire region becoming unstable. As a result, Iz and its environs suffered from sudden earthquakes and eldritch storms which transformed the landscape. This raw chaos made the area very popular with new arrivals from the Outer Rifts, easing their transition to life in the Universe.4
For additional as-yet unincorporated sources about this subject, see the Meta page.