Prime universe
(Capcom's primary storyline)
The Progenitor virus (始祖ウイルス?) was an ancient West African double-stranded RNA virus which was the basis of the bio-terrorist agent known as the t-Virus. Its ability to infect a wide variety of organisms, ranging from humans to animals, plants and even fungi is rarely present in single-stranded RNA viruses. It was a highly potent non-carcinogenic mutagen that became central in the Ndipaya culture.[1]

The virus reinforces certain characteristics by recombining the host's genes. Under special circumstances, it may cause spontaneous mutations.[2]

History of Progenitor Research



Stairway of the Sun.

"Stairway of the Sun" was first discovered by Westerners in the 19th century, and the virus that was extracted from it would become the base from which the Umbrella Corporation's most successful Bio Organic Weapons research would stem several decades later.[3]

The first Western account of the virus dates back to the work of Henry Travis, a man who mentioned the flower over a century before and was promptly discredited as part of a financial move by his brother to prevent anyone else capitalizing on the findings.[3] The next search for the virus began in the 1960s, initially by Lords Oswell E. Spencer and Edward Ashford in 1962, who learned of the virus through Travis' works.[4][excerpt 1] It was rediscovered in the Kijuju region of West Africa on December 4, 1966[5][6] during an expedition led by The Earl Spencer and Doctor James Marcus[5] (his student, Brandon Bailey, being among them)[5] after three months of searching.[5] Naming the virus within it "Progenitor", Dr. Marcus made preparations to leave Africa with a sample to begin his research immediately.[5][6]

Unfortunately for Marcus, the mass-cultivated flowers were found to not produce the virus and it was concluded by Bailey that local environmental factors were necessary for its cultivation.[5]


Despite months of cultivations using varying factors (different soil; temperature; water and light-exposure), the trigger for the virus' production could not be found.[5] Despite the lack of any real development, Spencer began making plans to set up a company in March 1967; while Bailey saw it as pointless without any progression with the virus,[5] Marcus went along with it for under the condition that it didn't interfere with his research.[6]

In November, Spencer began to show his true colors. After his private mansion in the Arklay Mountains was built to hide his Laboratory, he had the building's architect, George Trevor, his wife Jessica and daughter Lisa used as part of his research into the Progenitor virus. Only Lisa survived.[7]

A number of events, both good and bad, occurred in 1968: firstly, the African expedition began to push the Ndipaya out of their ancient, ruined city in order to locate the Sun Garden.[8] In July, Umbrella co-founder Edward Ashford became the first Westerner to perish from exposure to the virus.[7] The next month, with the Sun Garden secured, Marcus and Bailey set up a research station within the cave before Marcus was called up by Spencer to administrate the Umbrella Executive Training School, where Spencer continued to investigate the virus.[6][8] With the African outpost established in September of that year, Dr. Bailey began exporting newly cultivated samples straight to Marcus.[8]

Birth of Tyrant

In January 1978, James Marcus combined the Progenitor virus with leech DNA, creating the t-Virus.[6] In 1988, Dr. Marcus' two most valued (and, ironically, most trusted) assistants, William Birkin and Albert Wesker, would then assassinate Marcus at the order of his partner and fellow co-founder, The Earl Spencer. The two would continue his research from within the secluded Arklay Laboratory.[9] Here, under Spencer's supervision, Dr. Birkin continued to experiment on Lisa; these experiments led to the creation of the G-Virus at a much later point in time, discovered by mixing the Type-B Progenitor virus and the countless viral experiments made on Lisa and the NE-α Type parasite injected into her body.[9]

Path to Godhood

In 2006, The Earl Spencer in his waning years met with Albert Wesker to "pass the torch" on his plan of godhood. Spencer felt it was his right - and only his right - to become a god among men. There were multiple "Wesker Children"—children of intellectuals, hand-picked and programmed with Spencer's values—but only two, Albert Wesker and Alex Wesker, survived a screening trial using an experimental t-Virus variant designed to elucidate the Progenitor virus' superhuman traits. Upon discovering this, Wesker brutally murdered the decrepit president of Umbrella, and decided to use the power of Progenitor for his own gain by using it in the development of the powerful virus known as "Uroboros".


As the Progenitor Virus lies at the heart of international bio-weapons development, its original genetic material has been artificially-altered in many ways to suit the researchers' needs. In 1967, the virus was known to exist in two distinct strains - Types 'A' and 'B'.[10]


The Type-A strain was tested on Jessica Trevor on November 10, 1967.[10] The virus failed to fuse with her DNA and she was later killed.[10] It should be noted that she did not simply die from Progenitor, which were the fates of Marcus' human "test-subjects".[10] Furthermore, she managed to live for three days, with her brain in reasonably good condition.[10] Her mind was not fully intact, however, describing drifting into unconsciousness and memory loss in a letter.[10]


The Type-B strain was also tested on Jessica's daughter, Lisa on the same day.[10] This strain of the virus succeeded in fusing with her DNA, albeit with a delayed reaction.[10] Her brain - either due to the virus strain or her young age of 12 - was significantly affected by the virus, killing an imposter impersonating her mother five days later and losing the ability to write by November 17.[10] By December 4, all she could write was "I mis yuo".[10]

Over the years, Dr. James Marcus continued to alter the virus, eventually being satisfied with a mutation caused by exposure to leech DNA. This variant of the virus was of course "t", though at the time it was not considered a 'distinct' virus in name (as it became in the 21st century).

Further notes

  • Early on in the series, the virus was known as the "Clay Virus", with the t-Virus being the "ε-type" strain. The concept of the "Clay virus" was the brainchild of Kenichi Iwao.[11] The initial concept remains in the series, though additions to the lore in later games have since designated many of these types as components of the t-Virus program, rather than independent variants. Information on the virus was released in the INSIDE OF BIO-HAZARD guidebook and the Directors Cut re-release. An accurate translation of this information can be found on Project Umbrella .
  • The origin of Progenitor is only revealed in Resident Evil 5. The development of the t-Virus is revealed first in Resident Evil 0. The progenitor virus's origin and role were supposed to be bigger in Resident Evil 4 Prototype (Castle Version), with Spencer castle (the location of BH/RE4) being hinted at with paintings in Resident Evil (Remake).


  1. Excerpt from biohazard 0 KAITAISHINSHO, page 219:
    "アシュフォード家五代目当主エドワード、 友人のオズウェル・E・スペンサーとともに始祖ウィルスの捜索を開始。"
  1. Resident Evil 5 (2009), file: "Ndipaya Tribe".
  3. 3.0 3.1 Resident Evil 5, Tricell
  4. (in Japanese) biohazard 0 KAITAISHINSHO. Enterbrain. p. 219. 
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Resident Evil 5, From Chief Researcher Brandon's Journal - No. 1
  6. 6.0 6.1 6.2 6.3 6.4 Resident Evil 0, Marcus' Diary 1
  7. 7.0 7.1 Resident Evil 5, History of RESIDENT EVIL
  8. 8.0 8.1 8.2 Resident Evil 5, From Chief Researcher Brandon's Journal - No. 2
  9. 9.0 9.1 Wesker's Report II
  10. 10.0 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8 10.9 Resident Evil, Family Picture & Notes
  11. Hideki Kamiya Twitter post, 2011-06-22
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