This universe is introduced in the Mobile Suit Gundam IRON-BLOODED ORPHANS series, little is known about this timeline except that it takes place after what is known as the "War of Calamities".
The War of Calamities (厄祭戦 Yakusai-sen in VO) refers to the interplanetary conflict between humanity and the Mobile Armor, which became out of control before the adoption of the post-catastrophe calendar. This is the greatest war in history, which claimed the lives of 1/4 of the total world population and destroyed countless cities. Led by Agnika Kaieru and the original ancestors of the Seven Stars of Gjallarhorn, humanity finally won this long-running war some 300 years ago. This disastrous event had a great impact on the future world.
Chronology
The start of the Calamity War is the result of AI-equipped autonomous weapons systems spiraling out of control. Before the outbreak of the Calamity Wars, automated machines were a symbol of wealth and abundance, and humans actively promoted the automation of wars. With the risk of losing valuable soldiers reduced due to the weapons being controlled by AI, and the introduction of the semi-permanent Ahab Reactor as a power source, the Mobile Armor became the ideal weapon capable of effective combat. and sustainably. However, this ultimately led to tragedy. It's unclear exactly when this war was dubbed the 'War of Calamity', but the escalation of combat led to excessive AI evolution, resulting in other large-scale wars.
AI specializing in the destruction of enemy soldiers ended up expanding its target to all of humanity, whether friend or foe. It's unclear if this is due to human-made modifications or if it's the result of the evolution of AI. Eventually, the Mobile Armor gained additional self-proliferation abilities by creating, reinforcing, and developing various Mobile Armor themselves. It also became possible for Mobile Armor to independently produce unmanned subunits (the Pluma) that lack an Ahab reactor.
To end the threat of mobile armor, humanity has worked together, regardless of nationality, to develop various countermeasures. Notable examples include the nano-layered armor that rendered the Mobile Armor's beam weapons ineffective, the destructive electromagnetic projectile launcher called "Dáinsleif", and the humanoid weapon known as the "Mobile Suit" . Among them, the MS became humanity's primary weapon during war, and remained synonymous with mobile weapons even after the war. The MS has a humanoid form and is operated by humans, in order to prevent further loss of control of this armament, like the Mobile Armor, and also to end the war using humanity's own power. The MS can be seen as a simple amplified projection of the power of a human being.
MSs such as those using the famous Rodi Frame and Hexa Frame have been in use since mid-war, but even then they struggle to compete on equal terms with Mobile Armor, especially the newer ones. Additionally, the MAs had somehow acquired nano-layered armor technology, which made them difficult to destroy.
MS development moved to a new phase at the end of the war. In particular, the new Gundam Frame which was not only aimed at high performance, but promoted further integration of humans and machines with the "Alaya-Vijnana" system, which can be considered the ultimate human-machine interface. This system, which pursues the idea of "ending the war of calamities with human power", connects the human pilot directly to the MS, allowing the pilot to control the machine as if it were part of his body.
Another feature of the Gundam Frame is that it is powered by two Ahab Reactors, granting it additional power which was used on the rare occasions available to surgically strike the highly mobile Mobile Armor. It can be deduced that the Gundam Frame is extremely specialized in the fight against Mobile Armor. However, due to difficulties in making two Ahab reactors operating in parallel, only 72 Gundam Frames were deployed. This number was considered insufficient to stop Mobile Armor that had self-proliferation capabilities. It was therefore decided that cooperation with other MS and the use of Dáinsleif would play an important role in the war.
The Dáinsleif was one of the few weapons capable of penetrating nano-layered armor. However, due to its destructive power, it was not used on Earth given the post-war reconstruction. Instead, the Dáinsleif was used against Armor Mobiles on the Moon, resulting in heavy damage that altered the shape of the natural satellite, causing the Dáinsleif to be banned from use in the post-war period to reflect destruction inflicted on the Moon.
The formation of units deployed against Mobile Armor depended on where the battlefield was. On Earth and Mars, the Gundams served as the main combat units and destroyed the Armor Mobiles one by one with the help of other MS and support units. In space, Dáinsleifs were used as the primary weapon, and were assisted by MS, including Gundams, and other support units. On the Moon, MS teams like those deployed on Earth and Mars were also used in addition to the aforementioned use of Dáinsleif. Even with these powerful weapons and tactics, it still took time for humanity to end the War of Calamities.
Of the mobile suit pilots who fought in the war, none was more famous than Agnika Kaieru, who piloted the ASW-G-01 Gundam Bael , the first Gundam Frame. Since the Gundam Bael had no special weapons, Agnika was an extremely skilled person when it came to combat. He was later considered a spiritual pillar in the post-war reconstruction period. Agnika was also one of the founders of the peacekeeping organization known as Gjallarhorn. Gjallarhorn is ruled by the Seven Stars - family clans of seven Gundam Frames pilots who fought alongside Agnika during the war.
In PD 0001, the "Declaration of Vingólf" made by Gjallarhorn officially ended the War of Calamities, and mankind created a new social framework after reflecting on the causes of the war. As a result, the nations of the Earth were divided into four economic blocks: the Arbrau, the Union of the Strategic Alliance (SAU), the African Union and the Oceania Federation. Gjallarhorn used his military might to watch over the blocks and prevent the tragedy of the War of Calamities from being repeated again.
Additionally, restrictions and bans were placed on weapons that could be the deciding factor in a war. For example, the construction of new Ahab reactors has been restricted at Gjallarhorn, thus effectively limiting the development of new MS; the Dáinsleif has been banned because it can be used for mass murder; Gjallarhorn would manage the Gundams belonging to the Seven Stars, while the Gundams that could not be recovered would be abandoned after their cockpit, which contained the connecting piece for the Alaya-Vijnana System, was destroyed. The decision was also taken to make the implantation of mechanical devices into the human body taboo in order to prevent widespread use of the Alaya-Vijnana System.
These bans were also intended to allow Gjallarhorn to perform its duties smoothly, in other words, it is an arrangement to create a world where the organization can respond to any accident through its military might. However, if the situation gets out of control, Gjallarhorn has the option to immediately lift these bans in order to bring the situation under control.
Gjallarhorn also carefully researched Mobile Armor after the war, going so far as to seek out and destroy units that had become dormant. Despite this, as the War of Calamities has been fought on countless battlefields across the Earth, Moon, Mars, and space, it is possible that mobile armor will be found in unexpected places.
In PD0002, at the Malta Conference, the four economic blocs sign a treaty that divides and governs Mars. At their request, Gjallarhorn dispatches a vast force to rebuild the Martian government from its ruins.
The following year, Gjallarhorn redraws the borders of Mars. Each city is placed under the control of a land economic block. The Four Powers strive to recreate a government structure on Mars that ends up interfering with the affairs of the planet and turning it into a colony.
The Montag company is founded in PD0123 by Clive Montag, this company is in the reconstruction of the damage caused during the "War of Calamities".
Arbrau's government will grant limited autonomy to the territory she controls on Mars in PD0205. This action will be followed by the Oceanian Federation in PD0208 which will give autonomy to its Martian territories. It will be necessary to wait for PD0236 for the African Union to recognize in turn the autonomy of its territories on Mars. However, as Mars is subject to severe economic agreements, the planet actually enters into a context of front governments.
The economic situation on Mars maintains tensions within the different blocks and population, tensions are felt in PD0312. In PD0314, Kudelia Aina Bernstein makes a speech during the July assembly of Noachis, she calls for the economic independence of Mars vis-à-vis the Earth, it will be followed by sympathizing movements.
On October 31, PD0323, Kudelia Aina Bernstein called on the private company Chryse Guard Security (CGS) to escort her to Earth. The Gjallarhorn section in charge of this sector decides to attack the CGS base to prevent Kudelia from leaving. The ASW-G-08 Gundam Barbatos , used as a power source at the base, is reactivated by the soldiers of the CGS 3rd team, made up of children, in order to defend themselves from the assault on Gjallarhorn. 
Orga Itsuka, leader of the 3rd team, sets up a plan to take possession of the CGS, and thus protect all the children of his units. Together with the other members of their team, they found Tekkadan which replaces the company.
Tekkadan accepts Kudelia's escort request and launches it as the first mission in order to have funding for their actions.
Faced with the pressure of Gjallarhorn, Tekkadan heads for Earth, but without routes the journey will be long. They will meet the Turbines, a group made up entirely of women, with the exception of Naze Turbine, the boss of the company. Tekkadan and Turbines will face each other, the Turbines have indeed been paid by the former boss of the CGS, Maruba Arkay, in order to destroy Tekkadan. After the fight a discussion will bring the two leaders to fraternize, Tekkadan decides to join the Jupiterian group Teiwaz, of which the Turbines are a subsidiary, to exploit their discreet trade routes. Following his alliance with Teiwaz, the Tekkadans carry out a first mission for the organization by delivering goods to the Dort colonies.
During their journey, the Tekkadans and the Tubines will be attacked by the pirate group Brewers. After several fights, they will manage to get rid of their attackers but they will count losses in their rank. Notably Akihiro Altland's younger brother, Masahiro, who was a Brewers soldier as "human debris". The Tekkadans will get their hands on another Calamity War-era Mobile Suit, the Gundam Gusion .
Tekkadan arrives on the Dort colonies, precisely Dort 3, the goods of Teiwaz are revealed to be weapons intended for the working population who were preparing an armed demonstration against their working conditions. The workers' demonstration of Dort begins, it is held in front of the headquarters of the company running the Colony. Gjallarhorn goes on alert to repel the protest movement, orchestrating a fake attack on the part of the protesters, Gjallarhorn allows himself to retaliate and massacres the protesters, among the victims there will be Fumitan Admoss, being a servant for Kudelia, they have become friends, Fumitan had the mission to lead Kudelia to her execution in secret, but remorseful she threw herself in front of the young woman to save her.
With the help of her political supporters, Kudelia Aina Bernstein manages to lift media censorship and expose the barbarity of Gjallarhorn to everyone. Faced with this intimidation, the organization is forced to let Tekkadan go.
The Tekkadan manages to arrive in Earth orbit and finds itself confronted by the Earth Orbit Regulation Fleet led by Carta Issue. They will manage to cross the blockade and a detachment will arrive on the island where their meeting point is to lead Kudelia to her contact, Makanai Togonosuke, the former Prime Minister of Arbrau currently in exile. In order to accede to Kudelia's request, Makanai poses as a condition the fact of being able to speak before the parliament of Arbrau. The elections of the new representative having to take place, he must find the sympathy of the public to beat his adversary placed by Gjallarhorn. Kudelia accepts this condition and prepares with Tekkadan the trip to Edmonton, Arbrau's capital. They will be attacked by Carta Issue's Earth Orbit Regulating Fleet, Biscuit Griffon, Orga's advisor and co-leader of Tekkadan will be killed in action.
Using a different means of transport, the Tekkadans are still found on the way by the squadron of Carta Issue, after a fierce fight, during this confrontation, Carta Issue will be killed in battle. They will manage to arrive at their destination on time, friends a tough fight awaits them.
Using all means to block the road to Makanai Togonosuku, Gjallarhorn and Arbrau set up a blockade to prevent them from arriving in the city. Because of the prohibition to approach the Ahab reactors of a city, 
Tekkadans cannot use their Mobile Suits. Gjallarhorn will deploy one of its assets, the Graze Ein, which will wreak havoc within Tekkadan. Following a fierce battle going to the city, the Graze Ein will be destroyed by the Barbatos and Mikazuki Augus, Ein Dalton who is integrated into the giant Graze will be killed in battle, as for Mikazuki Augus, he will exceed his limits and those Barbatos, resulting in the loss of sight in his right eye and paralysis in his right arm, he regains his faculties when he is connected to Barbatos via the Alaya-Vijnana.
Outside of town, McGillis Fareed reveals himself to Gaelio Bauduin as being the one who allowed the Tekkadans to come to this and who used Carta Issue, Gaelio and Ein Dalton for his purposes. His goal is the reform of Gjallarhorn, Gaelio Bauduin will be killed in action by his friend McGillis.
Thanks to this support, Makanai Togonosuke will manage to return to the Parliament of Edmonton, he will give his speaking time to Kudelia who will then present the story of his trip from Mars and the highlighting of social inequalities. Following this speech, Makanai Togonosuke will be re-elected as Prime Minister of Arbrau, beating Henri Fleurs, his political rival.
Iznario Fareed, the patriarch of one of the seven ruling families of Gjallarhorn, will be forced into exile to hide his interference in Arbrau's affairs. Arbrau accedes to Kudelia's request and together they set up a reform project to deregulate the semi-metal produced on Mars. The Tekkadans are appointed strategic war advisors by Arbrau.
Faced with the loss of confidence in Gjallarhorn, the economic blocs decide to relaunch their armies in order to guarantee their own security.
In PD0325, Tekkadan is now a thriving business that has established its fame through its involvement in this conflict. The company has since opened a subsidiary on Earth to support Arbrau in the creation of an autonomous army. Their two emblematic Gundam finalizing their repairs and evolution following the damage suffered during the conflict, Tekkadan takes care of developing its resources in view of its new missions.
Tekkadan's historical client, Kudelia Aina Bernstein, then calls on their services again to escort her during a visit to one of the semi-metal mines managed by the Admoss company that she runs. The young woman is indeed again the target of political opponents, she will be the target of the pirates of the Dawn Horizon Corps, Tekkadan will defend her and repel the attackers.
Tekkadan will ask Teiwaz for permission to make an alliance with Gjallarhorn, indeed McGillis Fareed forms an alliance with Tekkadan in whom he sees a fighting force. McMurdo Barriston, leader of Teiwaz, supports Tekkadan, and allows them to disable the Dawn Horizons. A fight that will be led jointly by Tekkadan and the forces of McGillis led by Isurugi, his deputy. The Gjallarhorn fleet of Rustal Elion, commander of the largest starship fleet, the Arianrhod, is also present in small numbers to put spokes in the wheels of McGillis, however the Tekkadan will manage to capture Sandoval Reuters, leader of the Dawn Horizon Corps .
While on Mars Tekkadan must face the Dawn Horizon, the earth branch must face its share of problems. Still in his mission as military adviser, while the inauguration ceremony of the new military forces of Arbrau was about to begin, an attack targeting Togonosuke Makanai set fire to the powder. Chad Chadan will protect Makanai, but they will both be seriously injured and plunged into a coma. The SAU will be blamed for the attack, and another incident will lead to conflict between the two blocs. The conflict is in fact initiated by Rustal Elion, with the complicity of Galan Mossa, who will play the role of tactical leader for Arbrau and Tekkadan, whose communications with Mars are prevented by Radice Riloto, leading to confusion in the ranks of the young soldiers from Tekkadan. Takaki Uno will be in charge of Tekkadan during Chad's coma, he will lose his friend Aston Altland. McGillis Fareed is then sent there to put an end to the dragging conflict, Rustal Elion's plan being to make him lose face. McGillis will then have to face the Terran branch members of Tekkadan, they are unaware that McGillis and Orga have entered into a partnership. Mikazuki and other members of Tekkadan barely intervene in the conflict to put an end to it, but the losses are already substantial in the ranks of Tekkadan. Following this the Earth branch of Tekkadan will be closed and they will all return to Mars one month after the end of the conflict, with the exception of Takaki who will remain on Earth and leave Tekkadan.
McGillis will hold a meeting with Orga, asking him to ally with him in his plan to reform Gjallarhorn, he promises the boss of Tekkadan full control over Mars in terms of security and goods, they would be the Kings of Mars. Orga accepts the deal.
As Tekkadan receives new semi-metal mines from Teiwaz to manage as rewards for exploits against the Dawn Horizon, they discover a new Gundam Frame as well as a strange device. Tekkadan sends the information to Gjallarhorn, this strange machine turns out to be a Mobile Armor, Iok Kujan, Rustal Elion's deputy, decides to prevent McGillis from shining by destroying the Mobile Armor, but his intervention at the controls of a Mobile Suit will cause the activation of the cursed machine.
The discovery and awakening of the Mobile Armor, an autonomous device programmed for the genocide of humanity, causes the greatest crisis that Tekkadan will have to overcome. Accompanied by dozens of autonomous machines (Plumas), the Mobile Armor follows its program to the letter and heads for the most populated areas with a view to destroying them. Overwhelmed by the number of Plumas surrounding the Mobile Armor, Tekkadan is forced to ask Gjallarhorn for help in cornering the Hashmal .
Additionally, the Gundam Frames experience a strange phenomenon when approaching the Mobile Armor, the deactivation of the MS by the Alaya-Vijnana's security system. Mikazuki launches himself against the Mobile Armor in a fight of unprecedented violence and brutality, having deactivated the security of the Alaya-Vijnana he will manage to release all the power of the Barbatos, but this will cause him new physical consequences, with complete paralysis on its right side when not connected to the Barbatos. At the end of the fight, the different camps will review their objectives after this terrible ordeal.
The members of the Turbines still present with Tekkadan return to Naze Turbine, but the Turbines will be trapped by another member of Teiwaz, Jasley Donomikols. In cahoots with Iok Kujan, Teiwaz's second-in-command, sees an opportunity to eliminate Naze Turbine and Tekkadan. The Turbines find themselves alone facing the Gjallahorn, Teiwaz and Naze having explicitly forbidden Orga and Tekkadan to intervene. Iok Kujan launches an operation against the Turbines, making an unauthorized check he will pretend to find a prohibited weapon, the Dáinsleif (put there by his care), to declare the Turbines as an illegal enterprise. Naze will remain on the Hammerhead with Amida Arca to defend the other Turbine women during their escape, but Kujan will launch his offensive and target the Turbine member transport ships. Akihiro, Shino and Ride will intervene to help the women escape, against Naze's advice. Amida and Naze will sacrifice themselves to guarantee the escape of the members of the Turbines. McMurdo Barriston will then take care of the members of the Turbines, as promised to his friend Naze. Jasley Donomikols still wants to destroy Tekkadan, he will then perpetrate the murder of Lafter Frankland, which will provoke the Tekkadan.
Tekkadan will leave Teiwaz, with the goal of avenging the Turbines' death due to Jasley's machinations. The freshly mended Barbatos ( Barbatos Lupus Rex ) they go to war against JPT Trust. Jasley Donomikols feeling defeated calls for a ceasefire with Orga Itsuka, he refuses and orders Mikazuki to crush them, literally, he will slam his huge club down on the deck of Donomikols' ship, killing him.
Meanwhile on Earth, McGillis launches his coup d'etat, he takes possession of the Earth HQ of Gjallarhorn.
He activates the Gundam Bael, a symbol of Agnika Kaieru's thought, and a claimant to the legitimacy of Gjallarhorn's leadership. Rustal Elion will oppose this coup. 
Tekkadan joins the ranks of McGillis, and a fight will oppose the joint fleets of the revolutionaries, McGillis Fareed and the members of Tekkadan. A battle that will be won by Rustal, he had planned a Dáinsleif to be able to replicate with a full team armed with this forbidden weapon. In a desperate attempt, Shino Norba and his Flauros will use a Dáinsleif to destroy the deck of the fleet command ship Arianrhod, but it will miss its shot, and be destroyed as a result, Shino will lose his life in this final assault.
Tekkadan and McGillis will return to Mars, but the Arianrhod fleet pursues them. Tekkadan is the target of Rustal Elion's fleet, they will suffer many assaults, which will cause Tekkadan to be defeated. Before the last assault, Orga and Kudelia try to find a solution in order to protect the members of Tekkadan, but Orga will be shot while breaking out of Admoss society while trying to protect Ride Mass. Mikazuki and others, including Akihiro, will protect the retreat of Tekkadan members who will be forgotten, the remaining fighters will all perish on the battlefield.
Following the "McGillis Fareed incident" and the loss of the Issue, Kujan, and Fareed families, Gjallarhorn abrogates the Seven Star council system. The organization is restructured to be more democratic, ironically achieving the reforms McGillis wanted. Rustal becomes the new leader of Gjallarhorn, he also drastically downsizes the Martian branch of Gjallarhorn, leading to Mars' independence from economic blocs and the formation of the Martian Union led by the new leader Kudelia Aina Bernstein. He then concludes the Human Debris Abolition Treaty with the Martian Union, which aims to prevent further conflict and the exploitation of children as soldiers. He meets President Kudelia Aina Bernstein and promises her to support her efforts, when she references the destruction of Tekkadan and the noble death of Tekkadan members to motivate her goals, Rustal, amused, comments on how impressive she is .
Many members of Tekkadan will become Kudelia's bodyguards, others will seek revenge for their fallen comrades or join other groups, former friends of Tekkadan. Kudelia Aina Bernstein will keep her promise made to Mikazuki Augus and watch over the child he will have with Atra Mixta, his son, Akatsuki Augus Mixta Bernstein, whom he will never see. Atra and Kudelia got married and form the family they couldn't have had with Mikazuki.
Pieces
- Mobile Suit Gundam IRON-BLOODED ORPHANS (2 seasons)
- Mobile Suit Gundam IRON-BLOODED ORPHANS G
- Mobile Suit Gundam IRON-BLOODED ORPHANS Urdr Hunt