In the 1960s, Lord Oswell E. Spencer, Dr. James Marcus and his student Brandon Bailey discovered the Progenitor virus in West Africa. The Progenitor virus possessed mutagenic characteristics, which would drastically alter the physical and mental makeup of its host.

Marcus and Spencer planned to use the virus to create biological weapons, forming the Umbrella Corporation along with their mutual friend, Sir Edward Ashford. Following Ashford's death in an experiment with the virus,[citation needed] Marcus soon began to work on the prototypes of a malicious biological weapon.