The Resident Evil game series has to have the most complex and in depth histories of any video game franchise. In order to keep it all in order, below are two time-lines. The one on the left for the games. The right, the movies. Both timelines are in-depth and complex, featuring history from the entire series.
Game Series Timeline
1960: Technician Michael Warren begins Raccoon City's electricalization
The 5th Head of the Ashford Family, Edward Ashford, embarked on a mission to find the progenitor virus
1962: Ozwell E. Spencer asks architect George Trevor to design and build a mansion on the outskirts of Raccoon City
Nov. 1967: The mansion and lab facilities are completed in the Arklay Mountains
Spencer, James Marcus and Edward Ashford discover the progenitor virus that recombines a living organism's DNA
Dec. 1967: George Trevor dies at the mansion
1968: The construction of the Raccoon City streetcar begins in Europe, and the streetcars begin operating
Umbrella is founded as a pharmaceuticals company as a front for its true purposes
Jul. 1968: Edward contracts the progenitor virus and dies; Alexander succeeds him as head of the Ashford family
Aug. 1968: The Umbrella Training Facility is established in the Arklay Mountains. James Marcus becomes the first facility manager
Feb. 1969: Alexander begins a plan to build a facility in Antarctica. He secretly makes plans to build an underground laboratory there for the purposes of his private "Code: Veronica" project
Nov. 1969: The Antarctic Base and lab are completed
1971: "Code: Veronica" is a success. The twins, Alfred and Alexia are born
1977: Albert Wesker and William Birkin join the Training Facility as managerial prospects
Jan. 1978: Marcus succeeds in developing the T-Virus
Jul. 1978: The Training Facility is closed. Wersker and William bring the T-Virus to the Arklay facility to continue its research while Marcus continues his own research
Jul. 1981: William begins to see Alexia as a rival
At the age of 10, Alexia graduates a famous university at the top of her class. She them becomes the head research at the Antarctic base
1982: Alexia injects her father, Alexander, with the T-Veronica virus, but the experiment is a failure. Alexander is reported to have died under mysterious circumstances
Apr. 1982: Alfred becomes the 7th head of the Ashford Family at age 12
Dec. 1983: Wesker begins investigating secondary exposure to the T-Virus, and begins to doubt the direction Spencer wants to take Umbrella
1987: Michael Warren becomes Mayor of Raccoon City
1988: Wesker assassinates Marcus under orders from Spencer. William begins research to create the ultimate B.O.W., Tyrant, using the T-Virus
1991: Umbrella begins building a giant underground laboratory beneath Raccoon City
The "Nemesis Project" begins in the 6th European Facility.
Spencer approves William's G-Virus Plan, and work begins on it immediately. Wesker transfers to the Information Department
1993: Police Chief Brian Irons begins corrupt dealings with Umbrella
William transfers to the underground lab in Raccoon City, and makes a secret agreement with Brian Irons
Alfred graduates from a University in England, and begins work as managing director of the Antarctic Base. Rising up the ranks in Umbrella, he also becomes the commander in chief for Rockford Island
Dec. 1993: A training facility for Anti-B.O.W. squad members is completed
1994: John comes from a Chicago laboratory to replace William as head researcher at Arklay
Alfred builds a private mansion and a prison on Rockford Island
1996: Raccoon Police Department's special S.T.A.R.S. team is founded, with Wesker as the leader
HUNK (who later goes on to become a member of Umbrella's special forces) undergoes training at Rockford Island
May 1998: A huge quantity of waste products is dumped at the Umbrella Waste Disposal factory. Much of this leaks out before it can be disposed of
There is a large incident involving the T-Virus at the Arklay mansion. The lab there is abandoned
Marcus' close appears at the training facility
The first sacrifice appears, killed by Cerberus. The body of an approximately 20 year old woman is found in pieces
Jul. 1998: A number of people are reported missing near the mansion. The city sends S.T.A.R.S. Bravo in to investigate
Two separate investigative groups are sent to check out the Training Facility. The first one is wiped out by the B.O.W.s lurking there
The Bravo Team's helicopter makes an emergency landing in the Arklay Mountains due to engine trouble
Bravo Team investigates the Training Facility via the Ecliptic Express, and the Facility is destroyed
Alpha Team is sent out to search for the missing Bravo team
Wesker's true identity is found out by the leader of Bravo Team, Enrico Marini. Wesker kills him
Ravaged by the virus, the mansion and facilities are destroyed. 4 members of Alpha team (Chris Redfield, Jill Valentine, Barry Burton and Brad Vickers) and one member of Bravo team (Rebecca Chambers) return home
Wesker escapes the lab right before it's destroyed
Aug. 1998: Chris Redfield learns the G-Virus and heads to Europe to investigate Umbrella on his own
Sep. 1998: The virus spreads throughout the city due to rats that had become infected with it. Above ground the "cannibal virus" breaks out all over the city, and the area is declared a biohazard
William completes his work on the G-Virus
The Raccoon City Police Station is disbanded. Biran Irons goes mad, and the mayor leaves his daughter behind in Irons' care, while he escapes the city
The U.B.C.S. arrives in the city to rescue the survivors
Umbrella deploys its new B.O.W. Nemesis, into the city, where it begins tracking down former S.T.A.R.S member Jill Valentine, after killing Brad Vickers
Ada Wong is sent into the city to retrieve a G-Virus sample for Wesker, who lurks in the shadows
Umbrella also deploys several of its mass-produced Tyrants into the city, one of which to stop Leon and Claire from learning the truth
Leon and Claire escape the city together with William's daughter Sherry. The US military declares the area under martial law
Claire leaves Leon and Sherry to continue her search for Chris
Leon and Sherry are taken into Government custody, where Leon is offered a job within the President's secret service because of his work in Raccoon City
U.B.C.S. survivors are manipulated by the observer sent by Umbrella, Nicholai Ginovaef, and die off one by one. Raccoon General Hospital is destroyed
With Wesker's help, Ada barely escapes the city with her life, before destruction
Jill Valentine and Carlos Oliveira are rescued by Barry Burton, before the city is destroyed
The US Government decides to abolish all traces of the virus, and fire on Raccoon City with a nuclear missile, destroying it entirely
Claire is imprisoned while on Rockfort Island. Wesker attacks the island with his own private force, and unleashes the T-Virus all over the island
Claire escapes from the prison and sends an e-mail to Leon, asking him to use his new position in the Government to locate Chris and tell him where she is.
Having escaped from Raccoon City, Jill arrives at Chris' hideout, finding he's already left for Rockfort Island
Chris arrives at the island, only to be reunited with Wesker. Alfred escapes and heads for Antarctica
At the Antarctic Base, Alexia wakes from her cryogenic sleep. Alfred dies in her arms, shortly after
Claire and Chris and reunited at Antarctic, and together they manage to defeat Alexia. They escape in Chris' Harrier jet before the base is destroyed
2002: Leon and his partner, Jack Krauser, head to South America, to investigate the disappearances of many local girls. They soon find that the T-Veronica virus has reemerged there
2003: Chris and Jill reunite to take down an Umbrella lab in Russia, and destroy the newest B.O.W., T-A.L.O.S.
2004: Leon is sent by President Graham to Europe, to rescue his missing daughter, Ashley, and soon find that his old partner, Krauser, who he thought to be dead, is in fact alive, and responsible for her kidnapping. He also finds that Ada Wong, the woman he saw "die" in Raccoon City six years ago, is in fact alive, and working with Wesker
2005: Leon and Claire reunite in Harvardville, as another outbreak of the T and G-Viruses occurs in an airport, as well as a nearby lab, released by terrorist Curtis Miller
The company WilPharma, is revealed to be performing similar experiments that Umbrella Corporation dealt with
Leon and Claire, with help from Curtis' sister Angela, dispatch the mutated Curtis, destroying the viruses before they can be released further
TriCell purchases WilPharma, following the disaster in Harvardville
2006: Now B.S.A.A. members, Chris and Jill track down Ozwell E. Spencer in his new mansion, modeled closely after the one in Raccoon City, but find Spencer dead at the hands of Wesker
Jill and Wesker and both presumed dead after Jill tackles Wesker out a window to save Chris from his hands
Chris discovers Jill alive, and under Wesker's control, who is also alive, and him and Sheva struggle to free her from his control
Chris and Sheva track down Wesker, while Jill and fellow B.S.A.A. member Josh Stone, fight their way to rescue Chris and Sheva
Chris and Sheva kill Wesker, after he mutates, compliments of Uroboros. Chris, Sheva, Jill and Josh escape Africa with their lives.
Film Series Timeline
2002: The Red Queen "sterilizes" the labs beneath the mansion, killing all the scientists and workers beneath. Some gas is leaked in the mansion, causing Alice to lose her memory and pass out.
Soldiers storm the mansion, taking Alice and Matt with them down into the labs.
All of the soldiers are killed in one way or another, either by the Red Queen's hands or the work of the undead. Alice and Matt escape the labs, only to be apprehended by Umbrella scientists, including William Birkin, and because Matt's Licker scratch, he is taken into "The Nemesis Program". Alice is taken to the Raccoon Hospital.
Sep. 2002: After Umbrella scientists open the Hive, the zombies escape and the T-Virus infects the city.
Umbrella seals off the city, in their attempt to contain the infection.
The U.B.C.S. are sent in to help citizens escape the city and contain the infection.
Umbrella releases Nemesis, the mutated Matt Addison, and program it to kill S.T.A.R.S., including Jill Valentine, and fight Alice.
After defeating Umbrella officers and Nemesis, Alice, Jill, Carlos Oliveira, L.J. Wayne and Angela Ashford escape the city before an Umbrella launched missile destroys it.
Distracting Umbrella officers in order to give Alice and the others chance to escape, Jill is seized by the men.
2007: As the world lies in wasteland due to the release of the T-Virus, Alice evades Umbrella detection by moving on her own. She stays away from Claire Redfield's convoy after killing Angela Ashford while under Umbrella's control.
The convoy survivors fly to Alaska after getting information that it may be infection free.
Alice dispatches Dr. Isaacs after he mutants into a Tyrant, and finds her Umbrella made clones, planning to take them with her to destroy Albert Wesker and Umbrella in their Japan HQ.
Alice's clones are all killed in an explosion following their attack in Umbrella's Japan HQ.
Wesker injects Alice with a virus that strips her of her T-Virus granted powers.
Months later, Alice searches for the convoy survivors, only finding Claire under Umbrella control. She frees her of their control, and after finding Claire has amnesia because of the drug being pumped into her, they head to Los Angeles.
Alice and Claire find Claire's brother Chris locked up in a prison cell. Upon freeing him, the group heads to Arcadia, a roaming ship not far away. On the ship, they find Wesker alive, and fight him. Upon his defeat, he escapes. The helicopter he escapes in explodes after Alice planted a bomb on it.
Alice, Claire and Chris prepare for dozens of Umbrella soldiers flying onto the ship to attack, lead by a mind controlled Jill Valentine.
Most of the game history (1960-1998) comes from the source book, Resident
Evil: Archives. The film timeline, and game timeline (post 1998) all come from my own knowledge and the Resident Evil official Wiki.