There are two theories about how the Knahaten Flu was introduced to Tamriel. One account speaks of an Argonian shaman who, in retaliation for the awful treatment of his people by the other races, created the disease "through a manipulation of their cherished spore-trees" – the Hist. Another account attributes the disease to natural causes. Since Argonians were immune to the Flu, the former story was popularly accepted.
The Knahaten Flu began in the city of Stormhold in 2E 560, and quickly spread to every corner of Black Marsh and beyond, killing all infected non-Argonians. It continued to plague Tamriel for over four decades, the last known cases of the Flu being documented in the year 2E 603.
There is no definitive death toll of the disease. However, the Flu almost completely destroyed the non-Argonian population of Black Marsh, and instilled outsiders with a fear of the province for centuries. Only Dunmer slavers of House Dres, with their entire economy dependent on the slave workforce, remained there. It was said that even Tiber Septim himself thought twice before invading Black Marsh. Fear of the disease persisted late into the Third Era, when a mass panic was caused by an alleged relapse of the Flu.
Regardless of the Flu's source, the situation in Black Marsh became increasingly favorable to the Argonians after the disease struck. After the dissolution of the Second Empire, following the assassination of Potentate Savirien-Chorak, Cyrodiil lost its grip over most of the province. Once the Flu struck, the Empire lost any hope of controlling Black Marsh.
The Knahaten Flu was, indirectly, one of the main causes of the Alliance War. By destroying the royal family of Wayrest, it brought King Emeric to the throne from which he forged the Daggerfall Covenant. It was a crisis in Elsweyr, motivating the Khajiit to join the Aldmeri Dominion out of respect and gratitude for the many elves who had rendered aid during the worst years of the Flu. And of course, it provided the Argonians with enough independence to join the Ebonheart Pact as equals to the Dunmer, rather than as slaves.
The Flu also motivated changes to enforce higher standards in food quality and safety; for instance, it made the Summerset Navy rethink their regulations concerning rations.
Symptoms, Treatment and Transmission
Early symptoms of the Flu include "general malaise, loss of appetite, and fatigue," followed shortly by aching muscles, sharp pain in the shoulders, chills, and watering eyes. Late-stage symptoms include wracking cough, high fever, and blood flowing out of the nose, eyes and eventually the mouth. The most prominent sign of the disease was a red, granular rash, which did not itch but spread all over the body. Death usually occurred within three painful days of infection, but some victims were able to survive for up to a week.
While the worst of the symptoms could be alleviated by sorghum-tea and chicken broth, the search for a cure was impeded by many questionable alleged treatments. For instance, a Redguard named Perizada supposedly saved an entire village with a potion made by boiling clannfear claws in salt water, but she later succumbed to the plague herself.
How the disease spread is not definitively known. One source claims it was airborne, while another claims that it was spread through physical contact with the victim's particular rash. The latter theory is supported by reports that infected people who covered their rashes with clothing and bandages were less contagious. Though they were immune to the Knahaten Flu themselves, Argonians were often suspected to be carriers of the disease, perhaps due to the common belief that they had created it.
At its height, the Knahaten Flu engulfed most of Tamriel. It spread from Black Marsh, where it started, to southern Morrowind and across the Topal Bay to Elsweyr, and from there to Valenwood, Cyrodiil, Hammerfell, and even High Rock.
The Flu managed to destroy cities, religions, and even entire cultures. The high and mighty were not exempt, as it consumed the entire royal family of Wayrest, ending the Gardner Dynasty, as well as the hero Oreyn Bearclaw, who performed many good deeds in Valenwood before succumbing to the disease. Also in Valenwood, the Flu nearly wiped out worshipers of Z'en, leading to the Bosmer abandoning his worship entirely soon afterward.
The entirety of Elsweyr suffered greatly from the Flu, though the city of Senchal suffered the most. A strain of the disease crossed the channel in 2E 560 and infected most of the populace. Soon there was damage to the city itself, as paranoia raged rampant, and entire sections of the city were burned to slow down the Flu, never to be rebuilt again. An account from three hundred years later said that visitors to Senchal could still see the "charred skylines on the periphery, as black and jagged as the teeth of the nearest sugar junkie, begging for cake." The disease in Elsweyr was alleviated only with the help of the Altmer, who saved many lives, indebting the Khajiit to them. Despite heavy loss of life, the Mane's Legion managed to reimpose order and implement medical discoveries made by various Clan-Mothers.
The Kothringi and the Crimson Ship
Those most affected by the Knahaten Flu were the human population of Black Marsh. Most notable among them were the native silver-skinned Kothringi, whose settlements of Stillrise Village and Zuuk were already lifeless by 2E 561. The Kothringi are thought to have been completely exterminated by it.[nb 1]
One of the most famous stories from those troubled times is that of the Crimson Ship. Filled with Kothringi refugees, it left the shores of Black Marsh on the 9th of First Seed, 2E 563, only to be turned back at every port. After a year on the sea, they reached Hammerfell, and with no one to shelter them, they sailed west to the Abecean Sea, where the ship was found adrift by a group of pirates, its entire crew dead. To memorialize this event, the people of Hammerfell honor the 20th of Rain's Hand as the Day of Shame. Nobody leaves their house, for it is told that the Crimson Ship will return on this day.
- Thrassian Plague — An article concerning a disease of even more massive proportions.
- Diseases — An article detailing other, more common diseases of Tamriel.
- On the Knahaten Flu de Archivist Neleminduure — A description of the Knahaten Flu
- The Eagle and the Cat de Lord Gharesh-ri, Speaker for the Mane — A description of the outbreak of the Knahaten Flu
- The Ruby Necklace — A warning goes unheeded
- Pirates of the Abecean — A tale of a pirate crew's encounter with the infamous Crimson Ship
- Journal of Thracius Mento de Thracius Mento — The journal of a priest of the Divines
- Pocket Guide to the Empire, 1st Edition: The Wild Regions — Imperial Geographical Society, 2E 864
- [[Lore:Pocket Guide to the Empire, 3rd Edition/Argonia|]]
- Pocket Guide to the Empire, 1st Edition: The Elsweyr Confederacy — Imperial Geographical Society, 2E 864
- Tamriel Timelines, The Daggerfall Chronicles — Ronald Wartow
- Argonians Among Us — Sil Rothril
- Dreekius in Redguard
- [[Lore:Pocket Guide to the Empire, 3rd Edition/Cyrodiil|]]
- [[Lore:Pocket Guide to the Empire, 3rd Edition/All the Eras of Man|]]
- Triumphs of a Monarch — His Majesty King Emeric
- The Eagle and the Cat — Lord Gharesh-ri, Speaker for the Mane
- Introduction to the Lore of The Elder Scrolls Online
- The Epic of the Grey Falcon — Anonymous. Translated by Anido Jhone, Royal Archaeologist
- On the Knahaten Flu — Archivist Neleminduure
- The Ruby Necklace
- Journal of Thracius Mento — Thracius Mento
- Variedades da Fé no Império — Irmão Mikhael Karkuxor
- Holidays in Daggerfall
- Guide to the Daggerfall Covenant
- Tamrielic Lore — Yagrum Bagarn
- Knahaten Flu Confirmed — Shaman Chirah
- Drillk's Journal — Drillk
- Pirates of the Abecean