Albert Wesker is the main antagonist of the Resident Evil franchise. He is a high-ranking researcher of the Umbrella Corporation who also served as a double agent within S.T.A.R.S. as the captain of Alpha Team.
Wesker would later betray Umbrella and surface as a member of a mysterious organization looking to profit off of Umbrella's research. Eventually, Wesker would go on to pursue his megalomaniacal desires for world domination with the Uroboros virus, but he was stopped by Chris Redfield and the BSAA.