ID multiverse timeline (Doom 3 as sequel)

This is a timeline largely created by the Doom RPG/Wolfenstein RPG series and its connected Doom 3/RPG UAC lore website.

Background
The connected UAC Website itself was a tie-in to both Doom 3 and the Doom RPGlore.

Similarly the Doom 3 BFG Edition manual implies that the characters from several games are the same individual, and they represent his adventures):


 * Step into the boots of DOOM Marine and experience his adventures for the first time, or all over again.  Featuring enhanced versions of DOOM 3, DOOM 3: Resurrection of Evil and the all new DOOM 3: The Lost Mission, plus the classics DOOM and DOOM II, DOOM 3 BFG Edition is the consummate DOOM experience.

Interestingly the introduction seems to go as far to possibly suggest that the marine in Resurrection of Evil is the same marine as Doom 3 (which if true would have to suggest that Marine combat engineer actually did know the nature of the previous incident despite what the manual suggests). However, it also seems to imply that the Bravo Marine in Lost Mission is the same marine, but this is impossible as its timing overlaps with events of Doom 3 (only 6 hours into the invasion).

But much of this is ignored or made obselete by new Bethesda games both Wolfenstein (New Order/Old Blood) reboot and new Doom reboot (it is also unclear how much of Doom 2016 even fits with Doom 3).

ID Universe timeline
(Spear of Destiny/Wolfenstein 3D/Mission Packs, RTCW/Wolfenstein, Doom/Doom II/Doom 3/Doom RPG/Doom II RPG/Doom Resurrection, Orcs & Elves I/II, Quake III Arena, and Commander Keen)


 * 2-1,000,000 B.C. Ancient Martian civilization is built.
 * 400,000 B.C. - Height of the Martian civilization.
 * 90,000-10,000 - Ancient languages develop on earth, some may have originated from Mars.
 * 4000 B.C. - Swastikas appear on ceramics in Iran.
 * 100 A.D. - Germans begin using runes for magical and ordinary writing. They were able to use runes as a method of gaining insight into the future or the unknown by supernatural means (see Thule).
 * 918 - German Prince Heinrich I begins studying the Thulian Mystery Occults, and resolves to forge his own empire at the expense of the existing Frankish dynasty.
 * 933 - Heinrich I unleashes his army of undead on the invading Magyars, defeating them at the Battle of Riade.
 * 943
 * Heinrich I is sealed within his tomb by Simon the Wanderer.
 * The Defiled Church is built.
 * Unknown Date - The Spear of Destiny is found under Castle Wolfenstein in the catacombs.
 * August 15, 1911 - William "B.J." Blazkowicz is born in America (possibly in Milwaukee).
 * 1918 - End of WWI, the Spear of Destiny is one of the national treasures taken from Germany, and brought to a museum in Versailles, France.
 * 1929 -Geneva Convention bans chemical weapons.
 * 1933
 * Adolf Hitler becomes Chancellor of Germany.
 * Albert Einstein lives in California, but becomes a target of the growing Nazi might.
 * 1934 - The Totenkopf instituted by Heinrich Himmler becomes the symbol of recognition and loyalty to Hitler and his ideals. These were used on rings adapted Pagan Germanic mythology from Thor, and Wotan's spear.
 * 1937
 * Deathshead begins research into Super Soldiers.
 * 1938
 * As early as 1938, it was concluded that Operation Resurrection would require the development of an advanced synthetic humanoid host.
 * A very good year for wine, as the 1938 Latour proves.
 * 1939
 * Nazi invasions begin in Europe. Nazi Tanks roll into France, Hitler's armies retrieve the Spear of Destiny from Versailles, and bring it to Castle Nuremburg.
 * Einstein writes a letter President Franklin D. Roosevelt warning of German's advances in physics and warning of the possibility of Nazis developing a uranium bomb.
 * Operation: Resurrection is put on hiatus, after some major disaster at the Holstein dig.
 * 1940
 * Nazis conquer France (Operation Fall Rot).
 * April 16, 1940: War department records issued for Webley and Blazkowicz.
 * September 21, 1940
 * Jean Moulin briefs William Blazkowicz under a mission for the OSA in France. The French Resistance help B.J. infiltrate Germany. The Spear of destiny is recovered from Castle Nuremburg and demon is destroyed. The spear is brought back to the U.S. where it was kept under tight security.
 * B.J is honored by president Franklin D. Roosevelt for his actions at the White House in Washington D.C.
 * 1941
 * Hans von Schlieffen and a group of Storm Troopers travel to the U.S. to regain the spear. Hitler's forces recapture the Spear of Destiny again, but only the Axe escaped to the Nazi's Secret Scandinavian Base (built to carry out atomic research). Three intelligence agents are killed trying to infiltrate Hitler's headquarters. Admiral Powell of the U.S. navy sends B.J. to recover it.
 * 1942
 * January 10, 1942: Nazis begin working on human gene modification in an attempt to create a super soldier.
 * January 17, 1942: Experiments are successful. Soldiers begin to smuggle out super soldier cocktails to enhance themselves and sale on the Black Market.
 * February 4, 1942: Scientist tries one of the cocktails, and it works.
 * Sergeant B.J. is sent on a mission to stop Nazi forces near Castle Wolfenstein.
 * Olaric awakens from his tomb, kills the Nazis who awakened him, and is defeated for the first time by B.J.
 * Marianna Blavatsky is defeated for the first time, but she later recovers.
 * B.J. defeats Doctor Schabbs for the first time (or one of his relatives).
 * The Axis empire is at its height. While the Soviets battle the Axis in the East the remaining Allied forces damage and distract the Axis in the West until an amphibious liberation of Europe can be mounted.
 * The Allies concentrated their efforts in North Africa. Here the Axis Forces are ken to inflict further defeats and seize control of the oil-rich Middle East. The sands of the Sahara Desert is the first battle field, and hopefully not the last.
 * Over the course of a month, B.J. has his Original Encounter with Hans Grosse at Dresden, early Eisenfaust encounters, and battle with Adolf Hitler at Castle Wolfenstein. False end to the war..
 * July 14, 1942 - Operation Return to Castle Wolfenstein, Letter sent out to OSA agents..
 * 1943
 * 7 February, 1943
 * German signed top secret document.
 * Blazkowicz is reassigned to Libya to help fight against Erwin Rommel.
 * March 9, 1943 - The last Dark Knight is discovered. Zemph begins traveling to Castle Wolfenstein.
 * March 11, 1943 - Zemph arrives at Castle Wolfenstein.
 * March 12, 1943 - Agent Blazkowicz is reassigned to OSA. He and Agent One are sent from Libya to capture Helga von Bulow in northern Egypt.
 * March 13, 1943
 * Finished repairs and calibrations on generators at the dig site.
 * An attempt on Hitler's life is made. Henning von Tresckow asked Col. Heinz Brandt to take brandy on Hitler's plane. The attempt failed due to a faulty detonator.
 * The Axis High Command has ordered a strategic withdrawal from the 'remote and ultimately insignificant' North African theatre and their forces were busy fortifying the Atlantic coastline in expectation of Allied raids and an eventual evasion.
 * The Allies had much work to do before they could hope to mount a successful invasion attempt and had to gain expertise in both beach and parachute landings. Clearly, the next phase of conflict was critical.
 * March 14, 1943 - Blazkowicz and Agent One reach Ras El-Hadid. After failing to capture Helga von Bulow, they steal a Ju52 transport plane and fly to Castle Wolfenstein in northern Germany.
 * March 15, 1943 - Blazkowicz and Agent One are shot down over Castle Wolfenstein. They are captured by Helga von Bulow. Agent One is sent to Doctor Zee for torture and interrogation.
 * March 16, 1943 - Disaster at the dig site. Otto missing. The Royal Air Force raids Berlin, causing large fires and dozens of civilian casualties.
 * March 17, 1943 - Death of Agent One. Blazkowicz escapes Castle Wolfenstein and fights his way to Wulfburg Church. Helga von Bulow Summons Olaric. She kills Zemph and is in turn killed by Olaric. Blazkowicz confronts and kills Olaric (for the second time who had become more ghost like in his new form), and retrieves the Dagger of Warding, a mysterious Thulian artifact.
 * March 20, 1943 - Blazkowicz infiltrates Deathshead's rocket base at Katamarunde near the Baltic Sea, destroys an experimental V2 rocket and a prototype Mark I radar array.
 * March 21, 1943 - Blazkowicz infiltrates Katamarunde Airbase, steals the Bachem Ba317 Kobra plane, and flies it to Malta. That night, he is deployed to Kugelstadt, where he assists in the defection of one of Deathshead's research scientists.
 * March 22, 1943 - Blazkowicz infiltrates Deathshead's Secret Weapons Facility below Kugelstadt. Later in the day he is deployed to Norway, where he infiltrates Deathshead's X-Labs and destroys his first Übersoldat. Deathshead escapes and is promoted to General.
 * March 23, 1943 - Blazkowicz is deployed to Paderborn in the evening. He assassinates top officers of the SS Paranormal Division in Paderborn and in Chateau Schufstaffel. Blazkowicz infiltrates the dig site and returns to Castle Wolfenstein. Marianna Blavatsky resurrects Heinrich I to become the New Reich leader. Blazkowicz defeats the dark prince and terminates Operation Resurrection.


 * 1944
 * July 20, 1944 - An agent attempts to kill Adolf Hitler, with a bomb., however, Hitler survived the attempt.
 * The Spear of Destiny is recaptured by Hitler. Learning from his past mistakes, Hitler has expanded his subterranean command bunker beneath the chancellery in Berlin so that he can keep the Spear of Destiny nearby and well-guarded. Calling upon the dark forces of the occult, he summons Abigor, Hitler can see into the future and obtain the plans to future weapon systems. B.J. is sent to retrieve it again. He discovers, that the Nazi's are working with magic that allows them to see the future (even going as far to steal technology from the Union Aerospace Corporation). B.J. fights his way defeating Hitler's forces, but is transported to the Future onto a UAC Mars Base (c. 2140s). He defeats the Devil Incarnate and escapes. This apparently isn't the last time the Nazi's recapture the spear however.
 * Since 1944 global warming begins changing the Earth until it is unrecognizable in 2144.
 * A sci-fi movie "To Serve Man" about the 1950's is made.
 * 1945
 * February 1945
 * B.J. stops the German's deadly gas manufacturing.
 * B.J. destroys Operation Eisenfaust completely.
 * Blazkowicz defeats Hitler again. B.J. became a hero, and world famous, and met the President. The war was thought to be over, but the war continues...
 * Spring 1945 - To prevent allies from capturing the Totenkopf rings, Himmler ordered that Shrine at Wewelsburg castle be blast-sealed into the side of the mountain near the castle.
 * April 28, 1945 - The Spear of Destiny is finally captured by Allied Forces hopefully for the last time from Nuremberg. It is said General Patton discovered the spear, and the downfall of Germany began that day. On the same day Hitler committed suicide in the Fuhrerbunker with Eva Braun. It was fabled that the U.S. was destined to succeed Germany as the New World Power once ownership of the spear changed.
 * Operation Nichtsonne
 * The war ends in Europe.
 * October 23, 1945 - B.J. Blazkowicz's ID expires.
 * 1951 - Blazkowicz gets married to Julia Marie Peterson.
 * His son Arthur Kenneth Blazkowicz is born.
 * Date Unknown
 * - Arthur becomes a television host and changes his last name to Blaze.
 * Arthur marries Susan Elizabeth McMichaels.
 * 1982 - William Blazkowicz II is born.
 * 1990-1991
 * William Blazkowicz II (Billy Blaze) age 8 (Billy Blazkowicz shortened) using the alias of one of his grandfather's old WW2 buddies Commander Keen, saves Earth from many threats, even traveling to Mars.
 * 1993 - The date that original Doom was released, its setting and scenario is strangely similar to events that will happen in the future at least a hundred years later.
 * 2015 - Union Aerospace Corporation is founded by Thomas Kelliher on earth..
 * 2021-2022 (see below)
 * 2025 - UAC makes its name in the famous Joint Mars Expeditions.
 * 2078 - Destruction of the old Pentagon. New building designed to replace it in Wyoming.
 * 2095 - Great medical breakthroughs are developed over the next half century.
 * October 29, 2095 - Construction of Alpha Labs begins on Mars
 * 2104 - The explorations of the caverns in 2104 led to the discovery of ancient artifact codenamed U1, the Soul Cube, along with stone tablets written by the ancient Martian civilization.
 * 2112 - First structure of the first permanent Martian settlement is built, in what is known as Sector 4 (it is the oldest human colony on the planet).
 * 2114
 * Dr. Jensen received his Ph.D from Union States Institute of Technology, Northeast (USITNE).
 * October 10, 2114 - Birth of Ted Brown II.
 * 2115 - The initial chamber proving life once existed on Mars was discovered in 2115. It leads into what is now known as Site 1.
 * 2120 - Construction on Mars City begins.
 * 2122 - Dr. Kelvin begins working for the UAC.
 * 2126 - Military Council Ruling is inacted.
 * July 17, 2130 - The Alpha Labs are built.
 * 2135
 * 2138 - Dr. Jensen begins working for UAC's Advanced Research Department.
 * 2142 - Dr Jensen begins working on Mars.
 * 2143
 * Dr. Geurard joins the teleportation research team.
 * December 22, 2143 Chainsaw scheduled for refurbishment the following year. Zachary wishes everyone Happy Holidays.
 * 2144
 * Union Aerospace Corporation updates their website.
 * The military, UAC's biggest supplier, has used the remote facilities on Phobos and Deimos to conduct various secret projects, including research on inter-dimensional space travel.
 * January 8, 2144 Director Castle orders everyone not to tend to anything in the Atrium 02 until they find out what has killed everything.
 * January 12, 2144 - Xanax captures specimens following primary portal grid powerup. He successfully suspends them in stasis for further study.
 * January 13, 2144 - Zanax at the Lunar Outpost receives confirmation from Dr. Geurard on Mars that he has encountered similar fauna in his research.
 * January 16, 2144
 * M. Burns asks Chris to see what can be done about a unit. He couldn't touch the Echo Sierras until his new parts arrived from Earth.
 * J. Klein sees pressure anomalies in the coolant tanks at Cichus, caused by recent power spikes.
 * January 21, 2144 - Zachary looks for inconsistent behavior in computers at Tychus after reports.
 * February 4, 2144 - Zachary can't calibrate flow meters until Mixom tech gets down and serves a tank.
 * February 5, 2144  - Zanax at Keplar Site finds that the creatures are highly resistant to pain and injury, which has made specimen acquisition troublesome. It has been difficult acquiring them without killing them.
 * February 6, 2144 - Zanax research continues. He discovers from field reports that the creatures exhibit varying tolerance for different types of weapon attacks. He indicated that further research would be needed to discover most efficient way of subduing the creatures.
 * February 7, 2144
 * Third repair work order put in for the elevator in Keplar Site. It still hadn't been fixed.
 * X. Zanax on the Lunar outpost classifies specimen as an "imp" or possibly a "Gwocklego" according to his assistant.
 * February 8, 2144 - Zanax discovers that imp is particularly resistant to stasis suspension, but system is stable, but that that researchers should be careful when handling..
 * February 12, 2144 - J.Klein sees intermittent heavy loads on the power griad, but isn't able to find the source yet.
 * February 26, 2144 - Scientists in the Greenhouse at Keplar Site on the moon manage breakthroughs.
 * Febrary 27, 2144 - Cargo personnel begin reporting that their Manifest Database is having issues. A new power supply is ordered to see if it will fix the problem.
 * March 3, 2144 - R. Zachary installs new systems on the UAC Lunar Outpost, and Rhoomba 5000.
 * March 10, 2144 - Upgrades completed by Zachary. Everything checks out ok.
 * March 17, 2144 - Strange things begin happening to machines on the Lunar Outpost.
 * March 24, 2144 - Air, water and septic life supports still functioning but odd data reports. C. Sukut calls in a specialist. Zachary has gone missing.
 * April 27, 2144 - Dr. Kellyn McDonald's folder is checked and opened by Betruger, and then closed and locked.
 * October 10, 2144 - David Kramer forgets to send a birthday present to Ted Brown II.
 * 2145
 * Union Aerospace Corporation updates their website again.
 * February 5, 2145
 * March 11, 2145
 * March 13, 2145 - First Outbreak
 * April 5, 2145 - Samuel Harding
 * Dr. Nadira joins the Mars Outpost.
 * June 2145 - Experiment in the Delta Labs triggers an unknown event, resulting in the systematic invasion of the entire facility. Marine forces are deployed to hot spots around the facility, with many teams encountering heavy resistance. Bravo Team was ambushed in EnPro facility while searching for survivors. There was only one survivor of the team.
 * September 5, 2145 - Charles Hollies
 * September 8, 2145 - Pierce Rogers
 * September 14, 2145 - Andrew Chin
 * September 23, 2145 - Elliot Swann
 * September 24, 2145 - James Holiday
 * October 1, 2145 - Nick Sadowayj
 * October 2, 2145
 * October 3, 2145
 * October 5, 2145 - William Banks
 * October 6, 2145 - Karl Cullen
 * October 7, 2145 - Ben Wolfe
 * October 10, 2145 - Ted Brown II receives a birthday gift from Kramer, its hidden in secret room.
 * October 12, 2145 - Karl Cullen
 * October 16, 2145 - Seamus Blake
 * October 17, 2145 - Pierce Rogers
 * October 18, 2145 - Frank Delahue
 * October 19, 2145 - Larry Bullman, Grant Baston
 * October 20, 2145
 * October 22, 2145
 * October 23, 2145 - Gary Ross
 * October 24, 2145 - Frank Delahue, Jack Smith, Henry Nelson
 * October 26, 2145 - Michael Abrams
 * October 28, 2145 - Mark Lamia
 * October 30, 2145 - Bill Tyson, Anthony Garza
 * October 31, 2145 - Mark Lamia
 * Caldex is hired to work on the Lunar Outpost..
 * November 1, 2145 - Mark Lamia
 * November 2, 2145 - Mark Lamia
 * November 3, 2145 - Theresa Chasar (Doom 3)
 * November 4, 2145 - Jeffery Moen
 * November 5, 2145 -
 * November 6, 2145 - Anthony Garza
 * November 7, 2145 - Theresa Chasar (Doom 3)
 * November 8, 2145 - Adam Berneche
 * November 9, 2145 - Marcus Caseon
 * November 10, 2145
 * November 11, 2145 - Michael Abrams, Scott Johnson
 * November 12, 2145 - Marcus Stanton
 * November 13, 2145 - Frank Delahue
 * November 14, 2145 - Marcus Stanton, Robert Finch
 * November 15, 2145
 * The Doom Marine (B.J. Blazkowicz III) arrives on Mars on Transport 4409 as punishment for assaulting a superior officer for ordering his soldiers to fire upon civilians, and to replace another soldier. He and his body cast were shipped to Pearl Harbor, while the Marine were transferred to Mars, home of the Union Aerospace Corporation.
 * Daniel Young
 * November 16, 2145 - Elliot Swann, Ron Ridge
 * November 20, 2145 - The Recon Zulu marine team found only one survivor, a Marine Corporal. Important UAC personnel such the company's lawyer and counselor Elliot Swann and his bodyguard Jack Campbell, who arrived hours before the outbreak to make an assessment of the whole Mars operation and enact damage control if necessary, were found dead. Master Sergeant Thomas Kelly and other Delta Labs scientists were also found dead. The marine team had no information regarding the fate of Dr. Malcolm Betruger, the chief scientist of Delta Labs who - unknown to them - had become the demon Maledict.
 * The Marine (apparently known as B.J. Blazkowicz (Doom RPG) who survived the attacks in November returns to Mars to investigate strange reports going on there. Research continues at another base, the Mars Outpost. The UAC marinesare involved in the Mars Incident when demons take over the base. He defeats the diaboloical Dr. Kronos and his Cyberdemon creation in a showdown with the legions of Hell. There are no known survivors from the incident (it is not clear where the Marine ended up).
 * 2146
 * May 1, 2146, an orbital probe recorded a faint unidentified signal broadcasted from the abandoned Mars Site 1 complex.
 * August 6, 2146: Date tag on the new Mars mission Goals & Safety video.
 * August 8, 2146, the UAC board of directors announced the renewal of the Mars program, now led by Dr. Elizabeth McNeil, an ex-colleague of Betruger, who had transferred off Mars days before the outbreak and was the original one who requested Councilor Swann's presence on Mars. McNeil's main objective was to continue the experiments on Mars and discover what Betruger unleashed.
 * September 12, 2146: Elizabeth McNeil welcomes personnel to the Site 1 Expedition.
 * November 20, 2146 - Stan Blazkowicz travels to Tycho Station and saves the universe from demons, at one point even defeating the Harbinger, another Cyberdemon his ancestor had defeated centuries before.
 * November 27, 2146: UAC Lead Technology Officer releases the Ionized Plasma Levitator Briefing video.
 * 2147
 * March 17, 2147 - Resurrection of Evil begins.
 * 2148
 * Doom - The Doom Marine (B.J. Blazkowicz III) spending three years battling demons, and at Mars radioactive waste facilities is sent to Phobos after a distress signal is sent. He is forced to again fight demons on Phobos, Deimos, and then in Hell itself.
 * Doom II - The Doom Marine heads to Earth from a portal in Hell and sees that the Demons have begun conquering Earth.
 * Master Levels (Teeth) - The U.A.C. Marine is accidentally lost on Titan, the moon of Saturn.
 * No Rest For the Living - The Doom Marine stops another invasion by traveling to a Hell pocket universe to destroy another Cyberdemon from amassing an army.
 * After Hell's catastrophic invasion of Earth, the United States took steps to try to prevent another invasion from occurring. The old UAC corporation was re-founded, though it survived most its top level management had destroyed. It was turned over to strict government supervision, under completely new management (Final Doom).
 * It began to research tools and technologies to prevent future invasions from happening again (The Plutonia Experiment). With Earth invasion stopped, the remaining demons were gradually exterminated by mopping-up squads. The new UAC began working on quantum Accelerator devices, intended to close interdimensional gates at a distance and prevent future incursions. Scientists began to work with Gate technology again in order to learn how to close the Gates. This drew attention from beings from Outside. A new Terror began as a Gate was opene dup in the research complex. But the scientists were ready and closed the gate with their Quantum Accelerator Device, closing it instantly and permanently. The next day another invasion struck using seven Gates, while six of the gates were closed, the marines were not able to hold out, and everyone was killed.
 * The Marine who had been put on leave on a beach near by the complex was called in by the government to fight back and recover the Quantem Accelator and destroy the Gatekeeper guarding the last Gate of Hell. Being the only Marine left with no backup for an hour or two, he had to stop the Demon's plans or it would be too late. He took on the horde, to stop the Gatekeeper, and prevent another demonic invasion of the world.
 * The new government supervised UAC set up a new base on one of the moons of Jupiter (Io), as it continued its research into matter apportation and transportation under increased safety measures. They had hoped increased distance would enhance Earth's safety if something went wrong, and marines were stationed at the base, ready for anything (Final Doom: TNT: Evilution).
 * 2149
 * The Invasion of the Jupiter moon base began not long after the opening of the first Gate. The United States Space Marine Corps were prepared and won the battle. Research continued but less cautiously...
 * Several months later, believing that yearly supply ship was on its way, were caught in surprise as Demons attacked and invaded from space via flesh and metal mother ship. They were unprepared to fight an attack from above.
 * The Marine, now the marine commander was the only survivor left, as he was miles away from the base taking a stroll on the moon's surface at the time. He heard the sound reminding him of the nightmares he still had (from his previous battles with the demons). He returned to the base to discover his men dead, and vowed to take revenge (TNT:Evilution).
 * The Marine's (B.J. Blazkowicz) fatigue was enormous, his price for encountering pure evil (no mortal was meant to experience hell). The military doctors submitted him tests and treatments, which were of little help. The night mares continued. In the end by planetary policy, all was classified and sealed. The installations were sealed, and abandoned, and absolute quarantine guaranteed by apocalyptic levels of radiation (Doom 64).
 * October (Doom 2016) (see below).
 * Years Later
 * Doom 64 - A relay satellite activates after years of bombarding by neutrons and sends a final message to Earth showing energy signatures unlike anything sampled before coming from the abandoned installations. The classified archives were opened it was discovered that a single entity with vast rejuvenation powers, masked by the extreme radiation levels, escaped detection. It systematically borught he decaying dead back to corrupted living tissue (into something stronge and more vicious than before).
 * As the only experienced survivor, the tough Marine (B.J. Blazkowicz III)'s commission was reactivated and given the order for Mercilous Extermination. He returned to a space installation he once saved from demons, forced to kill the beasts again when they are resurrected, he travels back to their world (Hell) where he kills the Mother Demon. He decided to remain in hell to continue to battle the forces of hell to ensure that no demon arises again.

The GDF is a fencible military, as opposed to the Space Marine Corps which is expeditionary.
 * Outside of Time and Space
 * The Arena Eternal is an extradimensional structure created by the Vadrigar and populated with the greatest warriors in all of time and space. The Doom Marine, and other survivors of Phobos invasion: Crash, and Phobos were brought their from their eras to fight.
 * The Global Defense Force, or GDF, is a supranational paramilitary organization, formed in the mid-21st Century from a large pool of national military organizations and relief agencies, to combat increasingly severe weather events, other natural disasters and terrorist campaigns, as well as to keep the peace in historically unstable regions such as the Middle East. It was created shortly before the Strogg invasion of Earth.
 * The Strogg invaded Earth in the mid-21st Century in search of biological components. The Strogg invaded the Earth in the middle of its 21st Century period, taking its inhabitants completely by surprise. Their large invasion fleet arrived in orbit over the world seemingly out of nowhere, and its ground forces quickly proved themselves a dire threat to the existence of Mankind. By the mid-21st century humanity is fighting for its survival against the hostile alien threat seeking to end the Strogg once and for all by invading their homeworld.
 * How Quake fits into the shared universe is not clear, and there is little work done collecting the dates and timeline from that game and comparing it to Doom series (other than Quake 2/4 appears to take place during the mid 21st century, and majority of Doom takes place in the 22nd century), but could also take place in parallel universes that connect to each other. Doom III Arena's mentions that the Eternal Arena was built "millennia ago" and ties together Doom, Quake 1, and Quake 2 via several characters including Doom, Phobos, Crash, Ranger, Bitterman, Major Wayland, Tankjr, and Wrack.
 * In addition there are smaller side and alternate timelines from the novels. Note: Bethesda's latest Wolfenstein reboot series The Old Blood and the The New Order which follows Nazis winning WW2 is set in its own timeline as well, but likely doesn't connect to any Doom iteration universe (at least as of yet there is no evidence of space Nazi influenced UAC in the newest game.
 * Note: It appears that Doom Classic has to take place "after" Doom 3 in the "iD timeline"  due to the fact that Doom 3 marine has the same backstory as classic Marine. Whereas placing it as a prequel set in the early 21st century would seemingly cause a number of issues (assuming time travel/time dilation/etc is not involved). Noting that Dafydd novels did in fact introduce extreme 'time dilation' (adding 500 years between Doom 2 and the final novel), and Doom 2016 definitely brings up time travel, but if set after Doom 64 would likely cause issues (if Doom 64 is set before Doom 3), unless Doom 64 took place after Doom 3. For it to be the same Marine would make that marine over a hundred years old (or least had to have jumped forward in time via time dilation during his travels). It would also have to assume he either assaulted an officer again, or that the new command decided to return him to Mars for officer he assaulted over a century before. Also Deimos still exists at the time of Doom RPG and there are other nods alluding to Doom Classic will occur later. Lastly, 2018-2022 classic timeline dates, predates the joint UAC/Military 2025 Mars Expeditions mentioned in Doom RPG website. Unless there was an even earlier expedition, and the 2025 date was a second expedition.
 * Sam a droid that appears in Doom Resurrection, also appears in Doom RPG. His final outcome is confirmed in Doom RPG.