Resident Evil Nemesis EXPLAINED - Origins & Meaning
Umbrella’s Origins & The Birth Of The Virus
This international conglomerate was founded back in 1980 when the three initial members - Oswell E. Spencer, James Marcus and Edward Ashford - came together, but the former classmates and virologists were laying the groundwork for the company almost 20 years prior. See, Dr Marcus became obsessed with an elusive plant located in West Africa known as The Stairway of the Sun.
This plant became one that the Ndipaya people grew to obsess over, and even built their Kingdom around. It was said that if consumed, the plant would grant the chosen few the ability to gain enhanced superhuman strength and intelligence, but most that consumed the plant would become infected and die.
Eventually, the Ndipaya were all but killed thanks to animals eating the plants and destroying the Kingdom, but they would cling on until Umbrella took the Stairway garden for themselves and further research. This plant would serve as a foundation for the Progenitor and T-Virus down the line. This is were all the Viruses can be linked back to in one way or another.
Later Tricell would do the same under the leadership of Albert Wesker, but this would be years after the Raccoon City Incident.
However, the Tyrant Virus - best known as the T-Virus - wasn't made overnight, but finally came about once the Progenitor Virus was combined with Leeches (that you fight in the game) by James Marcus. These events are depicted in Resident Evil 0, which takes place shortly before Alpha Team are sent to the Spencer Mansion and encounter the undead. After the T-Virus was created, it meant Umbrella could finally start producing the virus on a large scale, testing it on all kinds of creatures.
Many of these would feature in RE0 and 1, but turns out a lot were in fact, accidents. That is why RE0 is plagued with a bounty of giant animal bosses.
Shockingly, a lot of this was all just so Oswell E. Spencer could fund his Wesker Project, getting him one step closer to becoming a God.