Power-hungry, intelligent and cunning, Albert Wesker was a man who sought power and domination over the entire human race, all for his own gain. To this end, he was affiliated with the Umbrella Corporation, as one of its most promising researchers, and at the same time participated in illicit activities by going undercover in the Raccoon City Police Department's Special Tactics and Rescue Squad unit (S.T.A.R.S.), becoming one of its team leaders. This changed before, during and after the Raccoon City Outbreak, where Wesker became affiliated with a mysterious group known as "The Agency", and became instrumental in bringing about the downfall of Umbrella, and later joined the "S" Corporation, while planning to recreate the world in his own image. Wesker is considered by many fans to be the primary antagonist of the Resident Evil series.
Albert was created as part of Project W, embryos merged with the Progenitor virus in order to create a super form of Humanity.
Wesker joined the international pharmaceutical enterprise Umbrella Corporation, at the age of 17 and began working as one of its researchers. In 1977, Wesker was assigned to the Management Training Facility under Doctor James Marcus. Wesker became friends with fellow trainee William Birkin, becoming colleagues and accomplices for years to come. Both Wesker and Birkin were regarded by Marcus as his best apprentices, and when the Training Facility was closed down on July 29, 1978, the two were personally transferred to the Arklay Research Facility (underneath Ozwell E. Spencer's estate) to continue their own T-virus research (while Marcus continued to work on his own), becoming the facility's chief researchers.
Wesker and Birkin's research of the T-virus lasted over 13 years and three different stages. In 1988, when the research reached its third stage (the creation of the Tyrant bio-weapon), Wesker and Birkin were then ordered by Spencer to assassinate their former mentor, Marcus and steal all of his research. Shortly after, Birkin's research yielded the discovery of the G-virus in Lisa Trevor's body. When Spencer approved his project in 1991, Wesker began having doubts about Spencer's intentions and requested a transfer to Umbrella's Intelligence Bureau that same year.
In 1996, Wesker formed the Raccoon City Police Department's S.T.A.R.S. unit and served as its captain and as leader of one of its two squads, Alpha Team. Two years after the formation of S.T.A.R.S., a series of homicides occurred near the Arklay region. While the public feared these deaths were the work of a local cult, only Wesker knew the truth. In an effort to control the public outcry, S.T.A.R.S. Bravo Team was dispatched to the region to investigate the situation. Wesker used the time they were gone as an opportunity to gather battle data by pitting the members of S.T.A.R.S. against Umbrella's Bio-Organic Weapons (B.O.W.s).
At the same time, Wesker and Birkin were ordered to reclaim the Umbrella Training Facility. Unfortunately, the resurrected James Marcus destroyed any chance of reclaiming it. Forced to destroy the facility, Wesker realized this to be the perfect opportunity to leave Umbrella to pursue his own personal interests. After barely escaping his superior Sergei Vladimir, Wesker prepared to dispatch the S.T.A.R.S. Alpha team to the region.
The following day, all contact with Bravo team was lost and Wesker's Alpha Team was dispatched to the site. Upon arrival, Alpha Team was attacked by Cerberus and then, abandoned by their pilot, Brad Vickers. After the loss of member Joseph Frost to the dogs, Wesker and the remaining members of Alpha team sought refuge in the nearby mansion, where Wesker had previously worked. Initially ordering everyone to split up, Wesker disappeared and left the remaining members of Alpha team (Chris Redfield, Jill Valentine and Barry Burton) to fend for themselves.
Of the nine S.T.A.R.S. operatives who entered the mansion (including Wesker himself), only the members of Alpha Team, along with Bravo team's Enrico Marini and Rebecca Chambers, managed to survive against the various creatures and bio-organic weapons that infested the facility. In order to ensure the downfall of the other members, Wesker used extortion in order to convince Barry to do his bidding (luring the others to traps) by threatening his family. When Enrico uncovered evidence that implicated Wesker and Umbrella, Wesker murdered Enrico. However, Chris and Jill learned the truth about Wesker and then, proceeded to foil his plot by destroying the T-002 Tyrant, along with the facility itself.
During the ensuing chaos, Wesker injected himself with a primitive variant of the T-virus given to him by his partner, William Birkin. After allowing the Tyrant to kill him, the virus reanimated his body. This gave him superhuman strength, agility and regeneration, but at the severe cost of the loss of his humanity. The resulting mutation also gave him gold-red cat-like eyes (but these are not immediately noticeable, due to the sunglasses he always wears). Wesker was revived, while the remaining S.T.A.R.S. operatives were convinced that he died in the explosion. After reviving, Wesker realized the S.T.A.R.S. had destroyed the Tyrant and escaped with their lives. He then tried to steal the data from the labratory, finding that Sergei had download the data to the Russian base and the Red Queen had locked Wesker from the mainframe system. He swore revenge against the remaining S.T.A.R.S. members and Sergei. His plans foiled, Wesker escaped the mansion.
With the combat data and embryos he acquired from the various B.O.W's from the mansion, Wesker was able to secure a high-ranking employment position within one of Umbrella's mysterious rivals; The Agency. He then began spying on Umbrella's activities. When Raccoon City suffered a T-virus outbreak, Wesker hired and sent a private agent named Ada Wong to retrieve the G-virus sample in the (unknowing) possession of William's only daughter Sherry Birkin, hidden within her pendant. While Ada lost the sample, she was able to secure another sample of the virus from William's remains (William had transformed into a monstrous creature after injecting himself with the virus, and as such was defeated by both Leon and Claire), but then lost the other sample to Umbrella Special Service (USS) Alpha team Leader (and sole surviving operative) HUNK, who was also sent from Umbrella's Paris Branch to secure a sample of the virus. After the Incident, Wesker, wanting to know about what other secrets Sherry might be hiding on her late father's behalf, had the Agency's spies in the U.S. Government keep watch over her. Wesker, who never underestimated Birkin, eventually had Sherry taken into custody and imprisoned, believing there was something more to her than met the eye.
Wesker and the Hive/Host Capture Force (HCF), a heavily armed Agency Special Forces Team, attacked the Umbrella facility on Rockfort Island, intent on retrieving a sample of the T-Veronica virus virus, created on Rockfort by Umbrella Chief Researcher Alexia Ashford. The attack succeeded, especially when the T-virus samples and captive B.O.W's in the laboratory section of the facility broke containment and contaminated the Island. However, Wesker and his men failed to find the missing Alexia. Wesker then went to the Antarctic Research Facility, which had also suffered a T-virus outbreak from infected Rockfort employees fleeing to the facility. It was here Wesker encountered his former subordinate Chris Redfield (who had arrived seeking his missing sister Claire). Wesker failed to gain a sample of the virus from Alexia, especially when he tried to use his own abilities to force her to surrender one, only to be driven back by Alexia's own abilities. While Chris fought and killed Alexia, Wesker was able to secure a sample of the virus from the retrieved corpse of Steve Burnside.
The base started its self-destruct sequence, but Wesker engaged Chris in combat, eager to settle the score. Wesker quickly used his immense strength and speed to gain dominance, with Chris refusing to allow Wesker an easy kill. Wesker was poised to deliver the finishing blow, only for an explosion, caused by the priming self-destruct, to knock a flaming pillar in between the two. Wesker, vowing Chris was lucky and next time they met he couldn't count on luck again, escaped the base as it began to crumble and explode around them. Wesker reached an Agency Submarine and sailed away. While the flaming pillar had badly burned Wesker's face, his burns healed no more than five minutes later due to his superhuman regenerative capabilities.
In February of 2003, Wesker infiltrated the Russian Umbrella Facility around the same time that Chris and Jill arrived to destroy T-A.L.O.S.. While his former subordinates managed to destroy Umbrella's final B.O.W., Wesker himself managed to kill the mutated Sergei Vladimir. He then took Umbrella data from the Red Queen, before deleting the computers memory, shutting down the facility. Wesker then took the information and uploaded it to the system within his operations center. Shortly thereafter, finally having strong evidence against Umbrella, he brought his findings to the court. With information from Wesker (who operated under the pretence of being a personal friend of the CEO), Umbrella was found guilty and officially shut-down, its top officials suffering legal troubles and an international manhunt began for Ozwell E. Spencer. With Umbrella's data in hand, Wesker had what he needed to create a new Umbrella of his own.
*Note: IF YOU HAVE NOT BEAT RESIDENT EVIL 5, DO NOT CONTINUE!!!!!!!*
Wesker continued to be flooded with questions regarding Spencer's true motivations regarding B.O.W's. In 2006, he discovered the whereabouts of Spencer and traveled there to find answers. Wesker expected Spencer to be surprised by his arrival, but much to his shock, the old man seemed to actually expect Wesker to arrive. It was then Wesker realized that Spencer had been in control of everything from the start, including Wesker's own actions. Spencer revealed that the development of B.O.W's was only a part of achieving his goal of forcing human evolution through viruses. With the birth of a superior human race, Spencer would make himself a god. Spencer required three things to accomplish his dream: the progenitor virus as a primary viral base, the Umbrella Corporation for funds, and people who would share his ideals when an advanced race came to be. Much to the surprise of Wesker, Spencer revealed Wesker to be the result of the third necessity.
In a plan called the Wesker plan, Spencer collected hundreds of children from parents of superior intellect throughout the world. These children were all given the surname Wesker, and Spencer used indoctrination and manipulation to install his values into these children. They were then put in controlled environments all over the world under Umbrella's watchful eye. These unaware children would continue to live their lives and received advanced education with the help of Umbrella. One of these children was eventually sent to Umbrella's training facility. That child was Albert Wesker. Spencer then gave all the Wesker children an experimental virus, Albert's being received through Birkin. The children were then programmed to seek Spencer out. However, all of Wesker's siblings were killed due to the virus. Wesker was the only one who survived. Unfortunately, now that the truth was revealed, the only thing impeding Wesker was an old dying man. Wesker killed Spencer by thrusting his arm through his chest, claiming the right to be a god was now his.
Just then, Chris and Jill entered Spencer's hiding place only to find Wesker there. Stronger than the two of them combined, Wesker sought his revenge on Chris once and for all. However, before he could deal the finishing blow, Jill sacrificed herself by pushing him out of the window, causing the two of them to fall into the chasm below.
The B.S.A.A. searched for the bodies, but were never recovered and the two were marked as deceased. In fact, the two survived and Jill was captured.
While putting Jill in a cryogenic sleep in the intention of turning her into a weapon against Chris, Wesker continued his activities. With the help of Excella Gionne and the Tricell Pharmaceutical Company, the old Umbrella research facility in Africa was reopened, along with a source for the progenitor virus. Now in possession of the mother virus, Wesker created Uroboros, the most powerful virus yet. With Uroboros, he planned to spur the next step in human evolution. Although the virus proved to be too poisonous for humans to be of much use, Wesker found a way to make the Uroboros less poisonous. In Jill were powerful antibodies that were made from her previous infection with the T-virus. Using these antibodies, Wesker was able to perfect Uroboros to suit his needs.
Using the newly discovered chemical called P30, Wesker attached a device on Jill's chest that would continuously inject Jill with the chemical. With this, he was able to bend Jill to his will and enhance her abilities. By doing this, not only would Jill continue to assist him and Tricell, but she would also serve as a method of revenge against Chris. At the same time, Wesker began placing the Uroboros virus into missiles with the plan of releasing it by jet into the Earth's atmosphere, causing a global outbreak.
Eventually, the BSAA would dispatch Chris and his new partner Sheva Alomar to capture and interrogate Ricardo Irving, who had been selling B.O.W.s in the black market. It didn't take long for them to find out what was really going on and for Chris to discover that both Wesker and Jill were still alive.
Eventually, Chris and Sheva would meet Wesker face to face. After revealing Jill to them, Wesker confronted his old nemesis. After a while however, he abandoned the fight to finish his plans, leaving Chris and Sheva to deal with Jill. But Chris and Sheva were able to remove the device from Jill's chest and free her from Wesker's control. Leaving Jill, they chased Wesker and Gionne onto the carrier ship they were planning to use to launch the jet.
Wesker would soon betray Gionne, infecting her with Uroboros. After Chris and Sheva defeated the monstrosity that resulted, they received a call from Jill. According to Jill, Wesker needed to inject a special serum into himself in order to keep the virus inside of him stable. If too much was injected, it would weaken him. In a previous encounter with Gionne, Chris and Sheva had obtained vials of the serum.
With this new knowledge, Chris and Sheva confronted Wesker on the ship's deck. As he engaged the two, Wesker revealed his plan to release Uroboros on the entire world and to rule over the newly created world as a god. Working together, Chris and Sheva managed to insert the serum into Wesker. Weakened, but not defeated, Wesker fled on board the jet, but Chris and Sheva managed to board it before it took off. In a tense battle, they fought Wesker as the jet continued to fly higher into the sky. With serum in hand however, Chris and Sheva were now more evenly matched against Wesker. During the battle, Chris opened the jet's underside hatch, causing the jet to lose pressure and crash inside an active volcano. Miraculously, Chris and Sheva survived the crash, but Wesker wasn't finished yet. Absorbing some of the Uroboros virus from a damaged missile, Wesker turned into horrific monster and engaged Chris and Sheva, determined now more than ever to finish off his hated enemy once and for all.
Wesker deliberately infected himself with the Uroboros in a last ditch effort to kill his nemesis. The tendrils wrapped around several shards of metal and circuitry before spreading to most of Wesker's upper body. The tentacles were elastic and Wesker swung his mutated right arm around like a spiked whip. The impact from these swings was enough to send a character into the lava. After taking several hits from an assortment of weapons Wesker mutated further. His left arm transformed and became a writhing mass of worms. First of all, at a certain distance, he'll grab you. Wesker's right arm could spin like a drill and then impale the character. His other attacks consist of a sweep attack, an attack in which he smashes the ground causing tentacles to grab your character from out of the ground,and an attack that is preceded by Wesker lifting his arm in the air.
Chris and Sheva were able to hold him off until the ground gave from under Wesker, and he fell into the lava. Still alive, he used his former left arm to grab hold of the evac helicopter that picked up Chris and Sheva in hopes of taking them with him. However, Chris and Sheva fired their RPG-7s at him, finally killing Wesker.