Knahaten Flu
The Knahaten Flu (Cyrodilic: Influenza Nahatenae), also known as the Knahaten Plague (Pestis Nahatenae) or Crimson Plague (Plaga carnilia or Plaga purpura), was a pandemic disease that affected Tamriel in the late 6th and early 7th centuries 2E.
The Flu originated in 2E 560 in the namesake Knahaten region of Black Marsh, near Stormhold, and spread rapidly throughout the province. Caedon, with its sizable Imperial population, was particularly hard-hit, as were smaller indigenous communities like the Kothringi and Lilmothiit, whereas the Argonians were largely unaffected due to their natural immunity.
A few months later, the Knahaten Flu crossed the Topal Bay to Elsweyr, and ravaged the port of Senchal. Scars from the plague are still visible here today, in the form of charred ruins, the remnants of Senchaliit neighborhoods that were burned down as buffers against the pestilence. The Black Kiergo district, which was consumed successively by plague and fire, derives its name from the blackened appearance of its oldest structures.
The Knahaten Flu ultimately disappeared in 2E 603, over forty years after it began.