Dishonored takes place in the industrial city of Dunwall, where technology and otherworldly forces coexist. The city's design is modeled on London and Edinburgh between the late 1800s and the early 1900s. The capital of the Empire of the Isles, Dunwall, is ruled by an oppressive regime that came to power following the assassination of the Empress and the kidnapping of her daughter. The city is a center for fishing and whaling; whale oil is a valuable resource which is needed to power the city. After a philosopher discovered that whale oil—known in the city as trans—can be used as a fuel, the government used it to develop powerful weaponry, which in turn bred government corruption. The city is stricken with a plague spread by rats, which is killing the poor and isolating the rich. The infected, known as "weepers", cry blood and can become violent. The government uses the plague as an excuse to take or purge citizens as they wish. Order is maintained by the Tallboys, heavily armored officers on tall, mechanical legs, and districts are separated by barriers known as "Walls of Light", which are made of energy and disintegrate unauthorized people who try to cross them. A covert group of activists, the Loyalists, plots to overthrow the government and install the Empress' daughter as the new Empress.

[from Wikipedia.org]