Nosgoth is a fictional realm that serves as the setting of the Legacy of Kain series. The world was created by Denis Dyack in 1993, and has since been expanded upon by the following games in the series. The history of Nosgoth is described as extremely vivid and intricate; there is a span of over two thousand years between the earliest era depicted and the latest.
As the majority of the games take place in the same limited area, it is unclear whether Nosgoth is the name of the entire world, or a region. Generally, the term Nosgoth is used to refer to the conceptual setting overall.
Time periods before Nosgoth begins to decay are used as settings in Legacy of Kain: Soul Reaver 2 and Legacy of Kain: Defiance. The landscape is diverse, including mountains, forests, plains and wetlands, and the climate appears to be temperate, similar to that of northern central Europe; the seasons are shown to change.
Blood Omen: Legacy of Kain, showcases a large area of Nosgoth while employing a similar variety of geographical features as the earlier period. However, the world is afflicted with plagues, haunted by dark creatures, and assaulted by madmen. Major human cities include theocratic Avernus, and Willendorf, a kingdom that wields power across Nosgoth, in the central areas. In the west the city of Coorhagen has been wiped out by plague, and in the northeast are lands controlled by the warmonger known as the Nemesis.
Soul Reaver 2 depicts a period one hundred years after Blood Omen, in which the decay has accelerated. Rain falls persistently and the landscape is populated with mutant creatures and demons. All human habitation encountered is ruined and unused, and death is everywhere.
Blood Omen 2: Legacy of Kain, set 300 years later, describes areas to the south of those seen in the rest of the series. The events of the game occur in Meridian, a large coastal city known as the capital of Nosgoth, and its environs. The city is experiencing an Industrial Revolution brought on by the technology of the Hylden. Ecologically, the world is quite frail. What can be seen of the countryside is an arid desert-like environment, with little flora or fauna remaining.
Roughly one thousand years later, in the period in which Legacy of Kain: Soul Reaver is set, the collapse of Nosgoth is nearly complete. Vampires choked the air with the smoke from massive furnaces, blocking out the sun in support of a vampiric empire, but that empire is waning. Towering cities and structures are inhabited only by occasional scavenging vampires. Humanity is nearly extinct, hidden in a heavily fortified citadel. The world is barren and lifeless, with a rocky landscape.
When the Pillars were raised, the original nine Guardians were vampires. Since vampires could no longer reproduce, a result of the Hylden curse, they would turn any new human guardians that were called to serve into vampires. This tradition continued until Moebius and Mortanius, who had been called to serve as Guardians of Time and Death, revolted against them and claimed the Pillars for humankind.
The Ancients were worshipers of the Elder God, and believed its doctrine of a pre-fated world. The Ancients eventually tried to convert the other chief race on Nosgoth at the time, the Hylden, to their religion, starting a war that proved devastating for both races. To end the war, the Ancients banished the Hylden to another dimension and raised the Pillars of Nosgoth to seal the passages between the two realms. Before the banishment could be completed, however, the Hylden cursed their enemies with sterility, a thirst for human blood, and immortality.
The Ancients and their history slowly died out over the ages, and the only one to survive long enough to be seen in the games was Janos Audron, who commissioned and guarded the Reaver, a weapon intended to be used by a prophesied hero who would restore the Pillars to the vampires.
Unlike traditional vampires, the species in Legacy of Kain has numerous means of propagation. While never explicitly seen to turn humans into vampires by the 'traditional' means of biting them, it is quite possible that they are capable of doing so. Another means of vampiric imbuement involves use of a relic known as the Heart of Darkness and necromantic rituals.
The descendants of Vorador constitute both the race of vampires descended from Janos Audron, Vorador and the Ancients, and the race created by Vorador himself following his supposed resurrection some time after the events of Blood Omen: Legacy of Kain. The vampires were massacred by the rising Order of the Sarafan, a sect of crusaders who strongly opposed vampirism. In the times during Blood Omen, a large portion of the vampire race dwells within the Termogent Forest regions.
After Vorador's apparent resurrection during the unchronicled events after Blood Omen: Legacy of Kain, Vorador uncharacteristically joined Kain in his conquest of Nosgoth. Vorador had the strength to create other vampires, and thus was instrumental in Kain's plans. Together, they raised a second vampire horde. This second race survived for centuries, despite being fervently hunted by the renewed Sarafan Order and its advanced technological Glyph Magic. They continued to exist up until the downfall of the Sarafan Lord, after which it is assumed that Kain, in his continued attempts to dominate Nosgoth, disposed of them before attempting to raise his own vampire lineage.
The history of the Hylden in Nosgoth is affected by the plot of the games, which uses time travel a great deal to affect the course of recorded history. In the original timeline (post Blood Omen 1, which itself had history being changed), the Hylden were utterly defeated without Kain even truly learning of their existence. The events of Blood Omen 2 and Kain's memory of having experienced those events were only brought into existence at the end of Soul Reaver 2, when Kain saved Raziel's life, thus allowing him to resurrect the ancient Janos Audron, whose blood was required to open the Hylden Gate, a portal between the Demon and Material Realms. After using Janos to open the Gate, the Sarafan Lord then used his powers to draw other Hylden into the Material Realm.
The name of the order was taken up again seven hundred years after the original order was disbanded by a mysterious entity known only as the 'Sarafan Lord'. In contrast with its benevolent appearance, the order was really concerned with the conquest of all of Nosgoth at which point they proceeded to instate a dictatorial rule over the land. This Sarafan Order shares nothing with the original save its name and desire to destroy the Vampire race.