Timeline of the Half-Life universe



"Time, Dr. Freeman? Is it really that time again? It seems as if you only just arrived."

- The G-Man

A timeline of the Half-Life universe can be made by gathering known dates. Several retcons having been made since the release of the first game, because it is still being written as of today (2011), and because technological limitations have changed in the intervening time, a complete official Half-Life series timeline will probably never be made, since it has made the writers contradict themselves and could limit their creativity for possible subsequent episodes. In spite of that, general events can be organized in a chronological order, around known dates.

1943
Cave Johnson receives the Shower Curtain Salesman award within Aperture Fixtures.

January
Cave Johnson appears in the UP Pioneer Press headlines for buying a salt mine in Upper Michigan, which is later reconstructed as the Aperture Science Innovators facility.

Between 1945 and 1954
Richard Keller is born.

1947
Aperture Science receives the award for Best New Science Company from the Science and Business Institute of America.

1949
Aperture Science is rated #2 among the Top 100 Applied Science Companies by the Mechanical Engineering World Journal (likely behind Black Mesa).

1950s
It is during this decade that the Black Mesa facilities are probably built, before being purchased and refurbished later by Black Mesa (several Half-Life texture files names contain the word "fifties", suggesting the facility is as old as from the 1950s). It is also possible the company existed in the 1940s, as evidenced by Aperture Science ranking second among scientific companies in 1949.

1952
Aperture Science is the Runner Up for the US Department of Defense's Contractor of the Year award, likely losing to Black Mesa. By now, Aperture Science has begun testing Repulsion Gel.

1953
Aperture Science constructs Pump Station Alpha and at least Test Shaft 09 Chambers 01 and 02.

1954
Aperture Science is the Runner Up for the US Department of Defense's Contractor of the Year award again, likely losing to Black Mesa.

1955
Aperture Science receives the Spirit of Idaho National Potato Board award for the promotion of Potato Science.

1956

 * The Eisenhower administration signs a contract with Aperture Science to manufacture shower curtains to all branches of the US Military, except the Navy.
 * Pump Station Alpha (which pumps Repulsion Gel) is in active use by now.

1957
Aperture Science constructs at least Test Shaft 09 Chamber 26.

From 1957 to 1973
Aperture Science produces mostly shower curtains, eventually making Cave Johnson a billionaire.

1958
Aperture Science constructs Test Shaft 09 Chambers 27 and 28.

June 15
Aperture Science's Test Shaft 09 "Zulu Bunsen" is condemned and sealed off.

Between 1963 and 1972
Colette Green is born.

1968
Aperture Science is involved in US Senate hearings regarding "missing astronauts". By now, Aperture Science has gone bankrupt. According to Cave Johnson, this is in large part due to Black Mesa stealing corporate secrets from them.

Between 1969 and 1978
Gina Cross is born.

1971
Aperture Science constructs Pump Station Beta.

1972
Aperture Science constructs at least Chambers 01 and 02 of the Propulsion Gel Testing Facility.

Between 1973 and 1982
Gordon Freeman is born.

1973

 * Aperture Science ceases producing only shower curtains.
 * This date is also the earliest known use of a bulletin board system by Aperture Science.

1976
Aperture Science constructs at least Chamber 05 of the Propulsion Gel Testing Facility.

October 17
Cave Johnson receives the answer to a confidential letter titled "Human Enrichment & Testing Initiative, Resource Acquisitions", describing the four types of Test Subjects and their behavior.

1978
Aperture Science constructs the elevator out of the Propulsion Gel Testing Facility.

Between 1978 and 1987


Adrian Shephard is born.

1981

 * Aperture Science constructs the Conversion Gel Testing Facility's enrichment center, and now performs tests on its own employees. By now, Cave Johnson has spent $70 million on moon rocks to grind up and turn into Conversion Gel, and as a result of exposure has himself become gravely ill and addicted to pain medication.

1982

 * Aperture Science constructs Pump Station Gamma and the Conversion Gel Testing Facility.
 * Cave Johnson names Caroline as his successor. When testing is complete, her intelligence is to be stored in his computer (likely running on GLaDOS).
 * This is the oldest known date of the Enrichment Center Test Subject Application Process being applied to Aperture Science's Test Subjects. It is operated by version 1.07 of GLaDOS, later "1.07a" and "1.09".

1983


For this year, a calendar named "The girls of Aperture Science" is issued by Aperture Science. It is unknown if it was issued each year.

1985
The Aperture Image Format is created.

1986

 * The Conversion Gel Testing Facility is updated with an additional wall.
 * Word reaches Aperture Science management that Black Mesa is working on a similar portal technology. In response to this news, Aperture Science begins developing GLaDOS, although the name was already in use in 1982.

1987
This is the most recent date for the Aperture Image Format. At that time, it is maintained by Doug Rattmann.

1996
After a decade spent bringing the Disk Operating System parts of GLaDOS to a state of more or less basic functionality, work begins on the Genetic Lifeform component. During that time, the Aperture Science Red Phone plan is implemented in case GLaDOS appears to become sentient and godlike, requiring an employee to sit by a red phone on a desk in GLaDOS chamber's entrance hall.

1997
At that time, GLaDOS's version is 3.11. This is also the latest known date of Aperture Science using a bulletin board system.

1998
Aperture Science releases the Propulsion Gel to the public as a diet aid, serving as a dietetic pudding substitute made out of liquefied, non-toxic fiberglass insulation and marketed under the name "Propulsion Pudding". However it is a failure and must be pulled from shelves. Later that year a new formula, the Repulsion Gel, is released, and is another failure. Both Gels are subsequently recycled for use with the ASHPD in Test Chambers instead. The same year, Aperture releases other testing elements, such as the Excursion Funnel, a tractor beam-like funnel made of liquid asbestos, the Thermal Discouragement Beam, a laser to be used with a Weighted Pivot Cube to destroy Sentry Guns and activate some buttons, the Aerial Faith Plate, a catapult plate flinging into the air Test Subjects or any other object upon contact, and the Pneumatic Diversity Vent, a variant of the Vital Apparatus Vent used for distributing objects to Test Chambers.

200-




This is the "year" during which the Black Mesa Incident occurs. Deliberately kept vague by the Half-Life team, it could be any date from 2000 to 2009.

Deduction points at "May 16, 200-" for the precise date of the incident. What follows are the different facts and clues leading to that choice:


 * The year "200-", first appearing in the Half-Life instruction manual, is given in every official source from the Half-Life story arc era.


 * Several entries from Adrian Shephard's diary are given in the Opposing Force instruction manual, written by Gearbox writers. March is used, corroborating the Raising the Bar date. Shephard says in his last diary entry, written on March 15, "We were told today to be ready in case it happens tomorrow.", suggesting that the incident occurs on March 16. It seems that the Gearbox writers replaced May by March: in the Half-Life instruction manual, Freeman is said to start working at Black Mesa on May 15 (later retconned to an unknown, earlier date), he is also said in the Half-Life PlayStation 2 instruction manual to attend the Hazard Course on May 16 at 7:30 (in a Hazard Course schedule with dates all set in May), and Barney is said to start is duty on May 16 at 9:00. Therefore May 16 appears to be the best day for the incident, and consequently March from Shephard's diary should be replaced by May, for consistency.


 * A calendar with the "Blue Marble" photo is also seen in the Half-Life chapter Office Complex, in the Opposing Force chapter Welcome to Black Mesa, in the Blue Shift chapters Insecurity and Captive Freight and in the Decay chapter Domestic Violence, always using the same texture file showing the December page. While the table was not made with much precision, December 8 and 15 start on a Monday, suggesting the calendar is from 1997 (so a year late), or 2003 or 2008, from when the date was known only as "200-".


 * While "200-" could refer to any date from 2000 to 2009, a note by series' writer Marc Laidlaw seen in Raising the Bar features "March 31, 2003", and a time, "4:33 p.m.". Although it has not been confirmed by Valve, it is possible that the Half-Life events originally were to start on March 31, 2003.


 * On March 24, 2010, an updated and expanded Aperture Science timeline originally given on ApertureScience.com in 2006 and submitted by Erik Wolpaw was published on Game Informer. Several dates were changed, and the last paragraph was expanded with facts suggesting that the Black Mesa Incident had occurred in 1998, the same date as that of Half-Life's release, instead of the original "200-". However Marc Laidlaw dismissed "1998" as the date for the Black Mesa Incident, as the date "200-" given when the first Half-Life was released is the only correct one. It is unknown why Erick Wolpaw made that mistake, and if it was intended or not. For convenience and consistency, that "1998" will always be replaced by "200-" on the wiki, even with the dates pertaining to Aperture Science.

Several days before May 16
The untested AI of GLaDOS is activated for the first time as one of the planned activities on Aperture's first annual bring-your-daughter-to-work day. Upon being activated, she almost instantly becomes self-aware, takes control of the Aperture Laboratories, locks everyone inside, and floods the Enrichment Center with a deadly neurotoxin, but is partially halted when she is quickly fitted with a Morality Core. She then begins a permanent cycle of testing, aimed at beating Black Mesa in the race to develop functioning portal technology.

May 3
From Shephard's diary entries (originally March; see above): "Another typically hellish day at base camp... I'll be glad when this is over and I can finally can get assigned a mission. There has been this really weird civie spotted at the base. Rumor is he's from some government branch looking to recruit; others say he's with some secret research group. I would jump at the chance to join. It would be cool just for the change and the adventure."

May 5


Gordon Freeman receives a letter from the Black Mesa Office of the Administrator's LM confirming he is hired.

May 7
From Shephard's diary entries (originally March; see above): "I finally saw the government guy today. I am not sure he is a g-man, but he was wearing a really uptight suit and carrying a briefcase. He looked more like a lawyer or insurance agent to me. I did notice him checking me out. Several times throughout the day I spotted him just watching me during training. I wonder what he's up to..."

May 9

 * From Shephard's diary entries (originally March; see above): "For weeks our drills have been the same crap day after day. Today we assemble for the morning run and our drill instructor tells us we have one week to become experts at indoor strategic combat. We will be spending every day this week at the combat simulation facility. As far as I know this a specialized training not taught in boot camp. What I want to know is if this is to test our ability to adapt or if we are being readied for a specific mission? Time will tell..."


 * Barney Calhoun receives a letter from L.M. about his May 15 reassignment to Blue Shift.

May 11
Colette Green receives a letter from the Black Mesa Office of the Administrator's LM saying that sample GG-3883 will replace sample EP-0021.

Before May 12
Barney Calhoun is performing a retinal scan and has his salary increased. His two-day Security Guard Training is scheduled.

May 12
From Shephard's diary entries (originally March; see above): "The rumors have been flying since our indoor combat training began. Most of my peers are convinced that we are being primed for a mission. No one can agree on what the mission is. I have heard the name Black Mesa Facility thrown around a lot, but I have no information about the place. The rumors are that some top-secret research is going on there. Doesn't sound too exciting to me..."

08:00
First day of Barney Calhoun's Security Guard Training under Miller's Holographic Instructor counterpart, in Sector A Training Facility. This is the Blue Shift Hazard Course.

May 13
Second day of Barney Calhoun's Security Guard Training.

10:30


Walter Bennet is being instructed by Gina Cross for an Anti-Mass Spectrometer Overload Simulation.

19:00
Colette Green was to be instructed by Isaac Kleiner for an Anomalous Materials Handling, but it was postponed to June.

May 15

 * Barney Calhoun is assigned to a 09:00 - 22:00 Blue Shift assignment until August 15 and reports at Area 3 Medium Security Facilities at 09:00. Other unknown security guards are assigned to Red, Orange, Yellow, Green and Indigo Shifts in specific areas of Sector A, B, and C. For that timespan, the Violet Shift is on standby.


 * From Shephard's diary entries (originally March; see above): "The rumor has been confirmed. We are being trained for a mission at the Black Mesa Facility. All I know is that the place is being used by scientists who are doing some kind of new research. I can't imagine what we would be needed for. We were told today to be ready in case it happens tomorrow. I don't know what "it" is, but the whole thing is a little strange. I kind of hope it doesn't happen; the mission doesn't seem to have much excitement potential. I'd rather hold out for something with more likelihood of combat."


 * This day was originally Gordon Freeman's first day of work at Black Mesa, but it was retconned in Half-Life 2 and its episodes, where it is implied that Gordon was already working for some time at Black Mesa before the incident: Barney tells Gordon he owes him a beer and reminds him who he is when first meeting in the City 17 Trainstation, and Alyx tells in the City 17 Underground that Gordon and Barney would compete in air ducts to get into Kleiner's office whenever he got himself locked out, among others.

20:30
Gina Cross is being instructed by Richard Keller for a Mark V HEV Suit Prototype Testing.

07:30
Gordon Freeman is being instructed by Gina Cross' hologram counterpart for an HEV Suit Training in Sector A. This is Half-Life's Hazard Course.

08:30
Several system crashes occur around Black Mesa (the security guard in the Sector C lobby states he has had a system crash "about 20 minutes ago").

8:42
Barney Calhoun starts his tram ride from the Area 8 Topside Dormitories at Black Mesa, to start his second Blue Shift day at Area 3 Medium Security Facilities in Sector C. He arrives there some time before 9:00.

8:47
After his HEV Suit Training, Gordon Freeman starts his tram ride from Level 3 Dormitories at Black Mesa. He is 30 minutes late.

Remainder of the day



 * The Black Mesa Incident. Around 9:00, Freeman conducts an experiment on sample GG-3883 in Sector C's Anti-Mass Spectrometer. The experiment goes wrong and triggers a Resonance Cascade, teleporting Xen creatures to Earth.


 * Freeman, Calhoun, Green and Cross fight their way through the facility.


 * Overnight, Freeman successfully launches the rocket.

19:00
As heard during the tram ride at the start of Half-Life, the Black Mesa Hazard Course Decathlon was to start in the Level 3 facility. This never happened due to the incident.

May 17

 * Early in the morning, Gina Cross and Colette Green are able to perform a resonance reversal. Their fate, along with Keller's, are unknown.


 * Barney Calhoun successfully escapes Black Mesa with Rosenberg, Simmons and Walter Bennet.


 * Adrian Shephard and his squad are attacked by Alien Aircrafts and their Osprey crashes. As Gordon Freeman fights his way across the surface towards the Lambda Complex, Shephard is left behind (this matches the message addressed to Cooper). Race X creatures appear sometime later.


 * Freeman defeats the Nihilanth and frees the Vortigaunts. He is then placed in stasis by the G-Man.


 * Black Mesa is destroyed by an atomic bomb. Shephard is also placed in stasis by the G-Man.


 * As the Black Mesa facility is destroyed, GLaDOS's race against Black Mesa is stopped.

08:00
Colette Green was to conduct a Public Relations Tour. This never happened due to the incident.

16:30
Otis Laurey was to be instructed by the Miller's holographic instructor counterpart for a Security Guard Training, but he apparently postponed and Cross suggests to Green to ask Barney to replace him. This never happened due to the incident.

August 15
Barney Calhoun's Blue Shift was to end on that day. It ended earlier due to the incident.

After May 200-


During this period of around 20 years Gordon Freeman is in stasis. It starts at the aftermath of the Black Mesa Incident in May 200- and ends at Gordon's arrival in City 17 in 202-.


 * Portal Storms rage on Earth while Xen creatures continue to be teleported. The governments and United Nations provide the protection centers located in major cities worldwide.


 * The Aperture Laboratories are in a lockdown, with employees still trapped inside. The number of Aperture Science employees also likely diminishes, until there are only a few of them left.


 * The Combine launches an assault on Earth. Earth governments and the United Nations enter into war against them. The Seven Hour War occurs. Finally, Earth surrenders to the Combine and Wallace Breen, former Black Mesa Administrator, is appointed Earth Administrator.


 * This is the period during which Portal is set. It occurrs a short amount of time after the Combine invasion of Earth.


 * In the Aperture Science computer-aided Enrichment Center, Chell is awoken by GLaDOS who makes her perform seemingly routine tests. However Chell soon learns that the Aperture employees are long dead or escaped, and that GLaDOS is seemingly the only being left in the decaying facility. After much promise of cake at the test's conclusion, Chell is met with an incinerator, which she narrowly escapes, and works her way through the maintenance areas, despite GLaDOS's protests. Eventually, Chell finds GLaDOS's control room, and manages to escape death by neurotoxin by detaching the GLaDOS's Personality Cores, and partially destroying her as a result. Chell is forced to the surface by GLaDOS's explosion, only to be dragged away from freedom and back into the facility by the Party Escort Bot. Unknown to Chell however, GLaDOS is still alive.


 * Doug Rattmann, being the one of the last Aperture employees alive, witnesses GLaDOS' destruction. After the Party Escort Bot drags Chell back into the facility, Rattmann feels guilty for Chell's situation and reenters the facility to help her.


 * At an unknown time before Gordon Freeman's awakening, Isaac Kleiner and Eli Vance each build in their respective labs a teleport not needing a Xen relay with the aid of Alyx Vance and Judith Mossman, among others. When tested on a cat, it kills it. They then continue working on it until Freeman's arrival.

One year before 202-
This is the last time Alyx Vance drives Highway 17, as said by her in the radio transmission at Shorepoint Base.

202-



 * Around 20 years after the Black Mesa Incident, Gordon Freeman is awakened by the G-Man after a long period of stasis. He explores City 17, encounters the Resistance and some of his former Black Mesa colleagues. Soon after he joins their cause in the war against the Combine and triggers the uprising of City 17 and his surroundings, becoming the primary target to the Combine. After destroying the Citadel's dark fusion reactor and defeating Breen, Gordon is called into stasis by the G-Man a second time.


 * Soon after he is freed from stasis by a group of Vortigaunts. Gordon and Alyx flee City 17 and proceed to the Resistance base White Forest, located in the Outlands.


 * The Resistance reverses the Combine Superportal, inflicting a consequent blow to the Combine plans, but unfortunately Resistance leader Eli Vance is killed by an Advisor at White Forest.

Pre-Portal 2
GLaDOS' partial destruction is followed by a period of inactivity within the Aperture Laboratories, during which time maintenance systems and Personality Cores maintain its functions. The facility remains in disarray, having become overgrown and dilapidated. Pre-recorded 'Emergency Test Protocols' can oversee test chambers in times cataclysmic system failure, "able to sustain themselves on a minimum 1.1 Watt". Chell spends this time in stasis until the events of Portal 2. For at least some of her stasis, Chell is under supervision by a remaining Aperture employee, Doug Rattmann.

The span of time between Portal and Portal 2 is not entirely clear. During Portal 2's opening sequence, an automated 'Courtesy Call' implies that Test Subjects in stasis are revived every 50 days. However, when the player is next woken, an autonomous P.A. system reports that the time elapsed is "99999...99...". It is unknown what unit of time it refers to. The presence of unrotted paper, wood & upholstered furniture throughout the game's environments would seem to support a timespan of decades (ex: 9999 days, or 27 years) rather than centuries, though this cannot be validated.

But if true, then the events of Portal 2 might coincide with the return of Gordon Freeman and the subsequent Uprising in around 202-.

Portal 2


After unspecified amount of time spent in stasis, Chell is awoken by Wheatley, a personality core. Wheatley insists he can secure an escape route out of the Aperture Laboratories, which instead results in the inadvertent reactivation of GLaDOS. As the story progresses, Chell finds herself traversing old condemned Enrichment Spheres originating from earlier than June 15, 1961, at which time Aperture Laboratories was under the direction of Cave Johnson.