The Progenitor Virus was the first mutagenic virus ever discovered and would become the base from which the Umbrella Corporation's most successful bio-organic weapons research would stem several decades later. The Mother Virus was discovered by Edward Ashford, and Lord Ozwell E. Spencer in an attempt to enhance its efficiency as a biological weapon. After being experimented upon by Dr. James Marcus, the Umbrella Corporation was then founded by the three, with Spencer providing most of the funding, to disguise the research they hoped to carry out. Dr. Ashford, who had high hopes for dramatic medical and scientific achievements through the study of the virus, died because of a Progenitor Virus infection in 1968.
James Marcus then combined the Progenitor virus with leech DNA, creating the T-virus. Dr. Marcus' two most valued (and ironically most trusted) assistants, William Birkin and Albert Wesker, would then assassinate Marcus at the request of his partner and co-founder, Lord Spencer, and continue his research from within the secluded Arklay Research Facility. Here, under Spencer's supervision, Dr. Birkin continued to experiment on Lisa with new variants of the T-virus. These experiments led to the creation of the G-virus at a much later point in time.
