Doom 4 timeline

This is the timeline from Doom (2016) which apparently takes place in an alternate timeline to the original series (but shares the same hero from both).

Background
Reboot universe's timeline is generally considered to be a parallel universe to the original Doom, or Doom 3. Though its not exactly clear how it ties into previous series, other than Doom 64/Lost Levels ties into it, according to the developers.

As for when Classic DOOM series takes place in its respective universe see Doom Timeline and Doom Retcon Timeline (with original interpretation that they took place in 21st century and later retcons implying they took place in the 22nd century).

In general there is too much overlap for events of classic DOOM to take place in the same universe as Reboot DOOM series. Although it is roughly possible that if DOOM 3 events are ignored the 21st century timeline could be the past of the Doom 2016 universe taking place century before Doom 2016 (see Worlds and Time). It would have to be assumed original military/industrial UAC evolved into the cult-like UAC over the century.

If Doom takes place in the same universe as Doom 3 (either as a prequel in the 21st century or retconned as a sequel in the 22nd), Doom Reboot universe would have to be entirely seperate and parallel as it overlaps with many of the dates of Doom 3, and UAC's more cultic nature does not fit with the more scientific nature of Doom 3's UAC. Though it might be possible that instead of classic doom taking place in 2022 (it would have to be closer to 2040 as per the Art of Doom's timeline).

It's less likely that if classic series took place in 22nd century since it too would overlap with the events of Doom (2016), and its history (and it seems "Our Hero'" had been hell for perpetually for a very long time according to The Lost Levels, Doom (2016), and Doom Eternal).

Regardless of which interpretations are believed, some kind of parallel universe and time travel does appear to be in place, see Worlds and Time. This timeline only covers the dates relevant and mentioned in the Reboot series (as there is no clear indication how it interacts with events of Doom 64, and when the date of that event took place, or what universe it took place in, in this reboot). Doom 64 is mentioned as a foot note...

Doom 64
21st or 22nd century (parallel universe)?
 * Doom 64 ends: The Doom Marine enters hell one more time and vows to fight demons for eternity to prevent them from invading earth again.


 * The Lost Levels: The sister Resurrector decides to take revenge on the Marine, sending him back to Earth. He fights his way through a UAC base to find a portal back to Hell, fighting his way through the new patch of Hell he finds the Mother Demon's sister again, and takes takes revenge on her. After her defeat he again decides to remain in hell walking the perpetual path through Doom.


 * He is discovered injured by the Night Sentinels who nurse him back to health and make him their Champion.
 * Worlds and Time

Ages

 * First age
 * Second age
 * Third age
 * Fourth age

Doom 2016
''Note: Most of these dates are also listed with the designation "MTC". This is a reference to "Coordinated Mars Time".  Some additional dates appears in The Art of Doom'', some of these dates appear to be from earlier concepts and in some cases shifted about in the final game see below.
 * 80 million years ago.
 * 60 million years ago.
 * 21st Century
 * Early; Water is discovered on Mars. Very little happens in way of colonization, except exploration over the next century.
 * Late; Advanced Rocket Launcher is developed.
 * 2019
 * Samuel Hayden is born.
 * 2095
 * The Argent Fracture is discovered. Argent plasma was discovered in a trench on Mars by an expedition from the SS Amundsen.
 * 2096
 * The Union Aerospace Corporation established an outpost on Mars to extract Argent plasma from the Argent Fracture.
 * 2122
 * March 10 - A statue of the Praetor Suit was excavated (Artifact U9) from Site 3.
 * 2124
 * November 16 - Two Ancient Sentinel statues were excavated (Artifact J46) from Site 1.
 * 2127
 * The Argent Tower is completed.
 * 6 Months Later - Samuel Hayden transfers his mind over to a cyborg body to continue his existence, after his body breaks down due to Stage 4 Cancer.
 * 2136
 * The Advanced Research Complex is completed.
 * 2143
 * During one of the first teleporter explorations, the Corrax tablets are retrieved from Hell in a UAC Automated Survey.
 * 2145
 * 128 - The first Project Lazarus Manned Expedition is sent to Hell. The expedition ends with complete loss of human life, but achieved its mission. The sarcophagus of the Doom Marine is recovered from Kadingir Sanctum.
 * 2146
 * Industrial accident related deaths in the Foundry dropped significantly thanks to new UAC safety protocols where employees exposed to dangerous materials are sent to the Lazarus Labs.
 * 351
 * The first Project Lazarus Tethering Operation is conducted.
 * Pinkies are discovered for the first time.
 * The "vade mecum" compendium is recovered from the Umbral Plains containing information on the Aranea Imperatrix.
 * 2147
 * 016 - The second Project Lazarus Tethering Operation is conducted. The expedition ends in an confrontation with the Hell Guard.
 * 2148
 * 177 - The second Project Lazarus Manned Expedition is sent to the Great Steppe. The expedition ends with similar losses. The petrified remains of a Baalgar demon is recovered.
 * 2149
 * c. February - The Argent Facility - UAC base had its last accident.
 * October - Doom 2016 Begins.
 * December - Indentured servants on the offworld Tei Tenga Mining Station were replaced with robotic workers, optimal output expected to return to normal by this date.
 * 2150
 * 2151
 * 2163
 * Doom Eternal begins...

Art of Doom (2016)
The Art of Doom has an early version of the timeline from the game its included here for comparison. Note: The book also mentions "AE" designation along with the "MTC" designation but there is no explanation (it is used for the 1366 date, and just talks about it being in UAC's archives).
 * c. 149 - First recorded trans-dimensional encounters with demons and humans apparently on Earth.
 * 1366
 * 88 - First time demonic races were documented by humans (this may also be associated with Argent D'nur).
 * 2049 - Plans for the colonization of Mars begins. UAC, Mixom and I/O Logistics lay down the foundation of a new civilization on Mars.
 * 2100
 * 000 - Early tethering operations firsthand discover possibility of species-demon hierarchy.
 * 2115 - A region known as the Well is discovered on Mars.
 * 2117 - Argent facility construction.
 * 2127 - Argent facility is completed on Mars. Samuel Hayden dies.
 * 2136 - Advanced Weaponry Division is completed.
 * 2143 - UAC automated survey.
 * 2144 - Early manned UAC Expedition to Hell.
 * 2145 -
 * 2146 -
 * 118 - Twins demon is discovered.
 * 351 - Pinkies discovered.
 * 385
 * 2147
 * 016 - They recover a hell warden.
 * 2148
 * 139 - Doomed UAC Trans-Dimensional Expedition most of the explorers were set upon by Barons of Hell.