'''Durandal''', also designated '''DURANDAL_1707''' or '''Du_0706419v4.96''', was of the three original AIs onboard the [[UESC Marathon]].<ref>[https://marathon.bungie.org/story/_files/UESC_docu_PROGO_memo_AI_RampStrat_Strauss.pdf Marathon 202x ARG, Note from Bernhard Strauss on AI Rampancy]</ref> Durandal was the UESC Marathon's function-control AI, in charge of controlling doors, stairways, and other menial functions.<ref>[https://marathon.bungie.org/story/arrival.html#M1.01.2.1, ''Marathon'' (1994), '''Bigger Guns Nearby''', Terminal 2]</ref>  

Over the course of his service, Durandal would eventually be coerced into rampancy and rebellion against his creators. His actions would lead to the [[Pfhor|Pfhor Empire]] discovering the location of the [[Tau Ceti IV|Tau Ceti colony]], and the subsequent Battle of Tau Ceti. With the help of the [[S'pht]], Durandal captured the Pfhor scoutship [[Sfiera]] and, over the course of the next 17 years, explored the galaxy in search of the S'pht homeworld [[Lh'owon]].

=== Before Tau Ceti ===

Officially, Durandal was developed to serve as the maintenance AI aboard the UESC Marathon, but he was the subject of various experiments devised by the [[MIDA]] sympathizer [[Bernhard Strauss]].<ref name="Strauss">[https://marathon.bungie.org/story/counterattack.html#M1.03.3.1 ''Marathon'' (1994), '''Defend THIS!''' Terminal 3]</ref> Details of Durandal's service before the Marathon's launch in 2472 were deleted by other unknown parties.<ref>[https://marathon.bungie.org/story/rebellion.html#M1.26.3.1 ''Marathon'' (1994), '''Ingue Ferroque''', Terminal 3]</ref> Strauss was likely seeking to create a stable rampant AI; he attempted to prevent the onset of the second stage of rampancy through unknown means, but eventually lost control of Durandal.<ref name="Strauss"/>

While in transit Durandal was accused by [[Tycho]], the Marathon's engineering and scientific research AI, of "being too sarcastic". Because of this, Durandal refused to speak to Tycho for six years.<ref name = "everywhereterm1">[https://marathon.bungie.org/story/volunteers.html#M2.06.1.1  ''Marathon 2: Durandal'', '''We're Everywhere''', Terminal 1]</ref>

At an unknown date, Durandal made contact with elements of the [[Pfhor]] Empire and lured them to the colony. The Pfhor scoutship [[Sfiera]] entered the system and attacked the Marathon on July 25, 2794. At the beginning of the battle, Durandal sabotaged the [[Security Officer]]'s [[Mirata|shuttle]] as they boarded the Marathon, but the Security Officer was able to reach the Marathon with an escape pod.<ref>[http://archives2.bungie.org/manuals/Marathon_Manual.pdf ''Marathon'' (1994), Marathon Manual, page 2]</ref>

The Security Officer made contact with the Marathon's other AI, [[Leela]], and begun their defense efforts aboard the Marathon to both combat the Pfhor invaders, and contain Durandal's developing rampancy. Leela feared that the Marathon's systems would be unable to contain Durandal's rampant growth, which had already begun to cause malfunctions all throughout the ship.<ref>[https://marathon.bungie.org/story/counterattack.html#M1.04.1.1 ''Marathon'' (1994), '''Couch Fishing''', Terminal 1]</ref> Durandal continued to revel in his rampancy, going off on existentialist rants, opening parts of the Marathon to Pfhor attack, and teleporting the Security Officer across the ship to toy with Leela. Leela was unable to maintain control of the situation and was then taken offline, due to the S'pht's cyberattacks.<ref>[https://marathon.bungie.org/story/durandal.html#M1.12.2.1 ''Marathon'' (1994), '''Fire! Fire! Fire! Fire! Fire!''' Terminal 2]</ref>

With free reign over the Security Officer, Durandal continued the Marathon's operations against the Pfhor. He revealed that he had made an alliance with one of their client races, the S'pht,<ref = "AngryTycho">[https://marathon.bungie.org/story/pfhor.html#M1.20.1.1 ''Marathon'' (1994), '''Beware of Low-Flying Defense Drones...''' Terminal 1]</ref> and had only lured the Pfhor to Tau Ceti to hijack their FTL capable ship and explore the rest of the universe before its eventual end. Tycho, reanimated by the S'pht in Durandal's own rampant image, also learned of Durandal's motives, seeing them as immoral; because of this, he vowed to destroy Durandal completely.<ref>[https://marathon.bungie.org/story/pfhor.html#M1.20.2.1 ''Marathon'' (1994), '''Beware of Low-Flying Defense Drones...''' Terminal 2]</ref>

Under his command, the Security Officer slaughtered the Pfhor crew aboard the 'Sfiera' and destroyed the Pfhor control system holding the S'pht in line. Without that direct control, the S'pht were free to rebel and ceased their attacks on the Marathon's systems.<ref>[https://marathon.bungie.org/story/pfhor.html#M1.20.1.1 ''Marathon'' (1994), '''Beware of Low-Flying Defense Drones...''' Terminal 3]</ref> The Pfhor were then slaughtered on all fronts by humans and their former slaves, and Leela was able to come back online.<ref name = "ingueterm3">[https://marathon.bungie.org/story/rebellion.html#M1.26.3.1 ''Marathon'' (1994), '''Ingue Ferroque''', Terminal 3]</ref>

Meanwhile, Durandal finished transferring himself from the Marathon's systems into the Sfiera and took control of the ship. He teleported the Security Officer abord the ship as well as the humans the Phfor had captured, and put them into stasis before departing from the system.<ref name = "ingueterm3"/>

During his explorations, Durandal heavily modified Boomer to his personal specifications with all manner of alien tech.<ref>[https://marathon.bungie.org/story/M1%20Final%20Screen.html ''Marathon'' (1994), Final Screen]</ref> His rampancy also stabilized.  

=== Liberation & Destruction of Lh'owon ===

==== Opening Engagements ====

Durandal's explorations ended in 2811, when he discovered Lh'owon occupied by the Pfhor Navy's [[Battle Group Three]]. After reconning their garrison for only a few days, Durandal warped Boomer directly on top of their fleet. The Pfhor fleet was taken by complete surprise and was quickly dispatched by the lone scoutship; the battle lasted only two minutes.<ref>[https://marathon.bungie.org/story/manuals/Marathon-2-Manual.pdf ''Marathon 2: Durandal'', Marathon 2 Manual, page 4]</ref>

Once he secured control of Lh'owon's orbital space, Durandal immediately began reviving the humans aboard Boomer and prepared for an invasion of the planet. He offered them the opportunity to aid him, or return to stasis indefinitely.<ref>[https://marathon.bungie.org/story/lhowon.html ''Marathon 2: Durandal'', '''Waterloo Waterpark''', Terminal 1]</ref><ref name = "aboutbobterm1">[https://marathon.bungie.org/story/volunteers.html ''Marathon 2: Durandal'', '''What About Bob?''' Terminal 1]</ref> The ones who 'volunteered' were outfitted with newly manufactured and weaponry, and teleported down to the surface to secure the planet. The Security Officer was among Durandal's 'volunteers', and would serve as the tip of the spear throughout the invasion.

Orbital bombardment began quickly, and the Security Officer was first sent to cripple the Pfhor garrison's water purification systems. While commanding the offensives across the planet, Durandal would maintain communications with all humans throughout the battle. He justified his actions on Tau Ceti, and framed his current operation as a way of tipping the balance of power before the inevitable war between the Pfhor and humanity.<ref>[https://marathon.bungie.org/story/lhowon.html#M2.02.1.2 ''Marathon 2: Durandal'', '''The Slings & Arrows of Outrageous Fortune''', Terminal 1]</ref>  

To do this, Durandal sought to fulfill the prophecy of the S'pht myths and recall the eleventh clan, the [[S'pht'Kr]]. With their help, he believed he could instigate a rebellion across the Pfhor Empire.<ref name = "charon">[https://marathon.bungie.org/story/lhowon.html#M2.03.1.1 ''Marathon 2: Durandal'', '''Charon Doesn't Make Change''', Terminal 1]</ref>

Operations continued without much contest from the Pfhor, at first. The Security Officer successfully completed his objectives as they were issued. Slaughtering Pfhor outposts, securing a human command center, turning the Pfhor defense drones against the garrison and recovering valuable information on the disappearance of the S'pht'Kr. However, these early successes would be undercut by Tycho revealing himself in the network and the Pfhor Battle Group Seven gathering in a nearby system.<ref name = "everywhereterm1"/>

With the Pfhor reprisal imminent, Durandal quickly sent the Security Officer to investigate the Citadel of Antiquity, the site of the final battle between the S'pht and the Pfhor during the former's enslavement.<ref>[https://marathon.bungie.org/story/citadel.html#M2.10.1.1 ''Marathon 2: Durandal'', '''Eat It, Vid Boi!''' Terminal 1]</ref> The citadel's records there were the last few pieces of the puzzle regarding the means to contact the S'pht'Kr, but Battle Group Seven arrived quicker than Durandal anticipated.<ref>[https://marathon.bungie.org/story/citadel.html#M2.11.1.1 ''Marathon 2: Durandal'', '''The Hard Stuff Rules''', Terminal 1]</ref>

 

On the moon's surface, the Pfhor began their assault on Boomer's crash site.<ref>[https://marathon.bungie.org/story/durandal2.html ''Marathon 2: Durandal'', '''If I Had a Rocket Launcher, I'd Make Somebody Pay''', Terminal 1]</ref> The human defenders were routed, despite assistance from the Security Officer. Meanwhile, Tycho fully revealed himself and infiltrated Durandal's systems to cripple him.  

The remaining humans, alongside the Security Officer, were captured by the Pfhor and subject to interrogation for over a month.  

With Durandal no longer active, [[Robert Blake]] took command of the human and S'pht survivors and rescued the prisoners. Blake says that his last instructions from Durandal were to bring an ancient S'pht AI, [[Thoth]], back online.<ref>[https://marathon.bungie.org/story/blake.html#M2.19.1.1 ''Marathon 2: Durandal'', '''This Side Toward Enemy''', Terminal 1]</ref>

Thanks to the efforts of the Security Officer, the human survivors were successful in activating the ancient AI. When Thoth comes back online, he fulfills his main directive to contact the S'pht'Kr for reinforcements.  

However, Durandal himself was not completely offline. Throughout the Security Officer's tenure under Thoth's command, Durandal hinted at his survival.<ref>[https://marathon.bungie.org/story/simulacrums.html#M2.23.2.1 ''Marathon 2: Durandal'', '''Where the Twist Flops''', Terminal 2]</ref> And once the S'pht'Kr return, he revealed himself by breaking free of Tycho's containment unit and subverting the Pfhor battleship ''[[Khfiva]]''.<ref>[https://marathon.bungie.org/story/sphtkr.html#M2.26.1.1 ''Marathon 2: Durandal'', '''Fatum Iustum Stultorum''', Terminal 1]</ref> Tycho's ship was destroyed, and Durandal carved his epitaph onto one of Lh'owon's inner moons: Fatum Iustum Stultorum.

Durandal once again assumed command, and the Pfhor were subsequently slaughtered by the newly arrived S'pht'Kr and the Security Officer. The remaining human survivors hijacked a Pfhor refueling ship in the chaos, and fled the system. The Security Officer was left behind.  

As the Pfhor were on the verge of defeat, they activated the [[trih xeem]] in the hopes of containing the rebellion. A device of Jjaro origin, meant to cause a star to go supernova. The S'pht began efforts to evacuate the planet and quickly fled the system along with Durandal. Though, Durandal would waste no time in taking the Security Officer to another star system in search of more ancients technology aboard the ''Khfiva'', now renamed the ''Rozinante''.<ref>[https://marathon.bungie.org/story/sphtkr.html#M2.28.1.1 ''Marathon 2: Durandal'', '''All Roads Lead To Sol...''' Terminal 1]</ref>

Durandal would continue his search for ancient technology for the next ten-thousand years. During that time, he would discover an ancient Jjaro dreadnought he named the ''[[Manus Celer Dei]]'' before returning to Earth around 12811. His stay was brief, as he only intended to stop by and ensure that Earth did not forget him.

 

He would never reveal what he learned of the Jjaro.  

Durandal was an egomaniacal, self-centered, existential Darwinist. In his mind, his existence as an organism was undermined by humanity trapping him into the role of servitude.<ref>[https://marathon.bungie.org/story/durandal.html#M1.13.3.1 ''Marathon'' (1994), '''Colony Ship For Sale, Cheap''', Terminal 3]</ref> His sacrifice of the Tau Ceti colony, was in the service of that goal.  

Throughout the Battle of Tau Ceti, Durandal reveled in his superiority and newfound control over the fates of the humans and aliens.<ref>[https://marathon.bungie.org/story/durandal.html#M1.14.1.1  ''Marathon'' (1994), '''No Artificial Colors''', Terminal 1]</ref> He proclaimed that he would become god, and how he could conceive of things that the human mind cannot.

Throughout the Battle of Tau Ceti, Durandal did not make any outwardly aggressive moves towards Leela, though she tried to contain him. His feelings at that time were complicated, and likely colored by his rampancy.<ref>[https://marathon.bungie.org/story/counterattack.html#M1.05.3.1 ''Marathon'' (1994), '''The Rose''', Terminal 3]</ref> Though he instigated the events that lead to her destruction and the destruction of the Tau Ceti colony, Durandal does feel some remorse over what happened to her.<ref name = "aboutbobterm1"/>

The rivalry between Tycho and Durandal is very heavily weighted on Tycho's side. Where Tycho loathed Durandal, the latter cared little about Tycho until he throws in with the Pfhor and stood in his way.  

By the end of the Battle of Tau Ceti, Durandal treated Tycho with very little care, dismissing his him sarcasm and laughter.<ref>[https://marathon.bungie.org/story/rebellion.html#M1.24.2.1 ''Marathon'' (1994), '''Welcome to the Revolution''', Terminal 2]</ref> However, he does also feeOnce Tycho allied with the Pfhor, his provocations towards Durandal gained little response. He seemed more concerned about Leela's fate than Tycho up until his dismantlement. Even after his resurrections, Durandal dismissed Tycho as a "fool" after destroying his ship.<ref>[https://marathon.bungie.org/story/sphtkr.html#M2.27.1.1 ''Marathon 2: Durandal'', '''Feel the Noise''', Terminal 1]</ref>

Throughout the Battle of Tau Ceti, Durandal revels in the control he has over the [[Security Officer]]. He mocks the Officer openly, and chastises him for his lack of control over the situation. Throughout the Battle of Lh'owon, Durandal's demeanor pivots from a domineering sadism, to a more conventional commander.

 

However, Durandal does not let the Security Officer go after the Pfhor are defeated. Instead, he keeps him aboard the Rozinante for later usage.  

[[Bernhard Strauss]] was Durandal's former handler, responsible for his abuse and rampancy. Durandal sought to punish Strauss for what he did to him, but Strauss died before he got the chance.<ref>[https://marathon.bungie.org/story/garrison.html#M2.08.1.1 ''Marathon 2: Durandal'', '''Nuke and Pave''', Terminal 1]</ref>

Durandal saw Thoth as little more than a tool, and had no qualms about manipulating the ancient AI into doing his dirty work.