- Main article: History
The King of Heroes who ruled Uruk and befriended Enkidu. During life, he had a key to the gates of his vault crafted, but he did not utilize it. The key was exceedingly ornate, and about the length and weight of a small survival knife. The jewels ornamented on the key were extremely valuable, both magically and monetarily. The key was filled with some magical energy of unknown origin. Viewing it as a trifle because there were none who would lay a hand upon his treasures, he threw it away. It eventually found its way into the hands of his summoner's ancestor, and while the key was filled with magical energy, he never found the vault. It stayed within his family until Archer's summoner used it to summon him instead of the first skin shed by a snake.
Normally, being summoned in an era where his property was sullied by the consumption society of the early 2000s, Gilgamesh would usually be in a worse mood overall. Only upon learning that his best friend, Enkidu, was summoned did he become more stable to the point where Gilgamesh abandons any of his usual conceit and carelessness. Traits that would normally greatly hinder Gilgamesh's combat capabilities.
He notably takes circumspect measures in order to protect his Master, Tiné Chelc, where Gilgamesh makes sure that Tiné is close to him along with putting up a Noble Phantasm that will automatically protect Tiné from incoming attacks. Gilgamesh tells Tiné that he can't allow her to die until he fulfills his promise with Enkidu. Gilgamesh is also otherwise more tolerant and forgiving of Tiné, as she is just a child from his perspective. Gilgamesh even calls Tiné his retainer; the overall Master and Servant relationship between the two is that they are highly compatible.
Within the World of Fate/strange Fake, Servant Archer Gilgamesh was previously summoned in the Fourth Fuyuki Holy Grail War and participated in the Fifth Fuyuki Holy Grail War. The Servant summoned in the False Holy Grail War is a new Servant without any memories of the Fuyuki Holy Grail Wars.
Archer is summoned by a magus wishing to restore his family's honor, but he is killed by another magus, Tiné Chelc, moments after the summoning is complete and becomes her Servant. She attempts to return the physical key of the Gate of Babylon to him, but he tosses it over his shoulder and says it is useless. After she introduced herself, Tiné then took Archer to meet the many people who wish to serve their king. Archer declared to Tiné that he was initially not interested in participating the War, and he would leisurely wait until a worthy opponent shows up, where he then took out the Potion of youth with the intentions of drinking it. However, as Archer learns that his best friend, Enkidu, was also summoned did he change his mind. After declaring to Tiné that she should rejoice in how she will witness her king fight with all his might, he then gives Tiné the Potion of youth where he declares he will no longer need it.
Archer faces False Lancer, whose identity is Enkidu, in the desert. Before even saying a word, Archer draws Ea, and unleashes Enuma Elish on Lancer. Lancer, however, unleashes their own Enuma Elish, which clashes with Archer's attack. After their clash, they proceed to banter on a bit, both being happy to see each other again. Archer then manifests multiple Noble Phantasms from his Gate of Babylon, launching them at full speed towards Lancer. Lancer though creates multiple weapons of their own from the earth, which they use to fend of the Noble Phantasms of the Gate. Their battle is, however, forced to stop when Lancer senses the approaching presence of a curse of death, which is especially harmful to them. Archer and Lancer clash one last time with the Enuma Elish, until parting ways, promising to face each other again.
After his battle with Lancer, Archer and Tine depart to the city, where Archer enters a casino along with Tine, who is invisible. Archer easily gathers a large amount of money, always winning thanks to his Golden Rule Skill. He and Tien also encounter Hansa Cervantes, the overseer of the Holy Grail, who acts friendly towards them. As Archer and Tine later patrol the city, they see the battle between Hansa and Jester Karture, a Dead Apostle who is also the Master of False Assassin. They are also spotted by Flat Escardos and his Servant, False Berserker.
Archer and Tine take residence in a large hotel. Tine expresses worry that the other Servants may find them, but Archer reveals that he wants the Servant who interrupted his previous battle with Lancer to come for him. However, instead of that Servant, they are attacked by a bowman who shoots an arrow towards them, specifically targeting Tine. This attack is blocked by a defense mechanism employed by Archer's Gate of Babylon. However, a second arrow passess through the defense, also aiming for Tine, but is repelled by Archer himself, who uses his armor to block it. Archer and Tine then board Vimana, the flying ship of Archer, and head towards the Servant who is attacking them. This Servant is, in fact, also an Archer, being the True Archer, one of the "True" Servants. Despite False Archer arriving and speaking to him, True Archer keeps on shooting at Tine, with his arrow being destroyed by Vimana's defense system. False Archer is annoyed by True Archer ignoring him, causing him to launch weapons from the Gate of Babylon towards him. True Archer, however, survives the attack, without a scratch. Now very angered, False Archer unloads numerous weapons from Gate of Babylon towards True Archer, but none of them are able to harm him. This is due to the cloth worn by True Archer, which defends him against any human weapons. True Archer says that False Archer will need to utilize Ea in order to even have a chance. Now intrigued of his opponent, Archer manifests Merodach, the second greatest sword in his treasury, secondary to only Ea, which he plans on using to test the might of True Archer. True Archer though remarks that he will die, manifesting a sash Noble Phantasm, which exerts a divine aura. However, before their battle can continue, True Archer is knocked away by True Rider, who arrives to the battlefield, also utilizing the same Noble Phantasm.
True Archer and True Rider then fight, while False Archer watches from the sidelines. However, after witnessing their power for some time, False Archer intervenes, telling True Rider that she is far weaker than him and True Archer, who is actually holding back against her. True Rider is aware of this though, only wishing to question True Archer on why he would attack Tine, a young child, without any remorse. True Archer notes that he isn't anymore the hero that True Rider knew. As they are all about to clash, they are trapped within an illusion by True Caster. True Caster also creates an illusion of False Lancer, which greatly annoys False Archer who physically responds by cutting the illusion, which caused Gilgamesh to unintentionally damage the Vimana by slicing the pilot throne. The king angrilly calls Caster an "imbecile, drunk on his own eccentricities". However, Caster manages to create a temporary truce between them, with False Archer and True Archer saying that they will meet again. True Archer also reveals his True Name, Alcides.
After the battle, Archer and Tine then return to the hotel, which Archer decides to decorate in a manner similar to Uruk. Though Tine says that it's beautiful, Archer is unpleased with the results, as it pales in comparison to Uruk. He even considers trying to create a royal palace or even a city to show the grandeur of Uruk. Tine eventually goes to sleep, while Archer stays behind. Archer notes that there are probably ten traitors within Tine's forces. He, however, chooses not to infrom Tine of this, as she should take care of her own forces.
False Archer later appears during the battle between True Archer against Clan Calatin and False Berserker, over the safety of Tsubaki Kuruoka. After False Berserker is transported away by his Master, Flat, False Archer mocks True Archer's appearance, after he steals the Noble Phantasm, From Hell, from False Berserker. Saber, False Assassin and Sigma, the Master of Watcher, also arrive on the battlefield, ready to fight.
False Archer becomes offended by Saber's presence and fires a volley of swords from Gate of Babylon at him, but he effortlessly bats them away with his own sword. Saber is amazed by the many high quality swords and asks False Archer if he can borrow a few. Even more offended, False Archer fires more swords, but Saber either bats them away or dodges them. Saber then offers to purchase a few swords, which makes False Archer even angrier. Saber then gets close and almost manages to strike False Archer, who blocks it. False Archer notices him seemingly using Magecraft to increase his agility, but he claims it came from one of his followers.
False Archer notices Saber dodging his swords like he had prior experience and expresses curiosity on how he has it. Saber explains that he sparred with False Lancer earlier, who fights in a similar way, and they became allies. In response, False Archer unleashes more swords and says Saber must pass his trial to see if he is worthy of being his best friend's ally. After hearing "trial", Saber asks if he is a Ruler, but False Archer points out a Ruler is an impartial judge while he is not. Saber then points out False Rider is on the loose infecting people with disease and asks if they can become allies to stop it. False Archer refuses and says he can deal with False Rider on his own. He fires a huge barrage of swords, so Saber dodges and parries them, then fires a blast from his Excalibur to knock several away. Saber boasts that False Archer outclasses him in many ways, but he's more than a match when it comes to speed.
Continuing to dodge swords, Saber manages to get close to False Archer and slash at him, but he jumps back in time. Saber fires a blast from Excalibur, but False Archer blocks it with several shields. False Archer mocks Saber because his Excalibur is just a replica of the real deal. To False Archer's fury, Saber steals one of the swords that he had fired and uses it to fire an Excalibur blast. False Archer blocks the blast with his shields again, but due to the higher quality sword, the blast is more powerful, so the impact knocks him into the air to his fury. Saber then blasts him again and again, sending him higher and higher into the sky.
False Archer is engulfed in the blast's light, but summons several weapons, links them together with the golden chain Enkidu, and disperses the blast. He then unleashes a rain of weapons on the church where Saber's Master, Ayaka Sajyou, is taking shelter. Saber blocks the weapons with his body and is impaled in several places. He crashes through the roof, but manages to stop the church from being destroyed. False Archer enters the church, ignoring the shocked Ayaka, and commends him for being able to stop his attack on the church and survive. The injured Saber scolds him for attacking a church, but he says he doesn't care about any institution for the gods. He says Saber trying to fight without any true desires was foolish, then says he will deliver his verdict and asks if Saber has any final words. Saber points out Ayaka has not done anything to him and asks that he spare her. False Archer says he will only grant her consideration, and if he judges her worthless, he will blow her away with the other rabble. He is about to declare his judgment on Saber, but is interrupted mid-sentence when True Archer fires an arrow at him.
False Archer blocks the arrow and berates him for interfering with his affairs. False Archer says he can defeat him and the corruption of the Black Mud, but True Archer says he can defeat him even though he is already dead. False Archer fires a barrage of weapons at True Archer, but True Archer either shoots them out of the air or expertly twists his body to protect himself with the Pelt of the Divine Beast. True Archer then loads an arrow coated in Hydra venom into his bow and fires it while using the Noble Phantasm Nine Lives, causing the arrow to turn into nine arrows that twist through the air seeking their target. False Archer says he can easily counter the attack, but is shocked when his Gate of Babylon portals suddenly close. He gathers the weapons he has already summoned and tries to deflect the arrows, but a loud roar sounds that distracts him with fear. An arrow pierces his shoulder, arm, and leg before spears of earth rise from the ground to deflect the rest.
Fillia appears riding on True Berserker and explains she retrieved the physical key of the Gate of Babylon that he threw away and used it to close the portals so he would lose. Although she has Fillia's unfamiliar face, he recognizes her as being possessed by Ishtar. Though suffering from the venom, he remains upright and insults her, then recognizes True Berserker as well. Ishtar turns to leave, saying a servant of Ereshkigal or Nergal is coming, but as a parting shot, has True Berserker impale him. As he slowly loses consciousness, a wave of blackness washes over the street. When it passes, False Archer and all the other combatants have vanished, to the shock of those observing.
It is revealed that Tine and Enkidu retrieved his body and returned to the hotel. For all of the previous day and this day, they have been trying to heal him, but it doesn't seem to be working. Tine is about to collapse from overusing her Magic Circuits, then Enkidu tells her to give up and accept Gilgamesh's death, but she refuses, saying she must save her king. Enkidu's Master, Wolf, encourages him to help her, so he heals Tine and they keep trying to heal him.
- Main article: Abilities
Gilgamesh has access to the Gate of Babylon and Ea. He has shown being able to clash with False Lancer, using Enuma Elish, creating a huge crater when they clash. He is one of the strongest Servants in the Holy Grail War of Snowfield, to the point that he is not concerned with the other Servants, apart from False Lancer. Orlando Reeve is most worried about his strength, and he plans on using his force to overpower him with multiple Noble Phantasm imitations before he can retaliate. Flat Escardos also noted that Archer could kill him and his Servant instantly.
Inside the Gate of Babylon, he has access to an essentially unlimited number of Noble Phantasms. These include Vimana, a flying aircraft, Merodach, the original sword of succession that he uses to test opponents, flying disks that act as a defense mechanism against attacks and the Potion of Youth, that allows him to transform himself into his childhood form. Archer also has shown possessing Sha Nagba Imuru, a clairvoyance Noble Phantasm that allows him to see nearly all possibilities in the world and even look through parallel worlds. However, he rarely uses this Noble Phantasm and is unable to see the timeline of the Fuyuki Grail Wars due to the mud of the Holy Grail clouding his sight.
 Fate/strange Fake - Volume 1 - Servant status: Archer
Master: Tine Chelc
True name: Gilgamesh
Alignment: Chaotic Good
Noble Phantasm: EX
■ Magic Resistance: C
■ Independent Action: A
■ Golden Rule: A
Fate which revolves around how much riches one acquires in life.
■ Divinity: B(A+)
Skill that shows how much Divine Spirit aptitude, how related one is to a god, one has. He was suitable for the highest rank but since he loathes gods it is Rank-Downed.
■ Enuma Elish: The Star of Creation that Split the Heaven and Earth
Type: Anti-World Noble Phantasm
Maximum Targets: 1000 People
Using the Sword of Rupture Ea to cut space. It is a power used by the gods when they separated the heaven and earth. As for power it is possible to say it is an attack close to the very top of all Noble Phantasms. By receiving the support of Noble Phantasms in the treasury, damage is further increase
■ (Obscured in volume 2)
Max Targets: ???
■ Gate of Babylon: King's Treasures
Type: Anti-Unit Noble Phantasm
The Golden City that is the King's Treasury, moreover the golden key connected to it. Treasures such as many Noble Phantasm prototypes, or the models of humanity's inventions from all times and places, these rare items were stored. They can be taken out freely. Naturally whether or not they can be handled depends on the user.
身長・体重： １８２ｃｍ ６８ｋｇ
■ 対魔力： Ｃ
■ 単独行動： Ａ
■ 神性： Ｂ（Ａ＋）
乖離剣・エアによる空間切断。神が天地を開く時に使用した力であり、威力としては有りと凡ゆる宝具の中で最 も頂点に近いと言える一撃である。宝物庫にある宝具の支援を受けることにより、ダメージの値が更に上昇する 。
黄金郷である王の宝物庫と、それに繋がる鍵剣。数多の宝具の原典、あるいは人類の発明のひな形や古今東西の 財宝、珍品が収納されており、自由にそれを取り出す事ができる。当然ながら、扱えるかどうかは使う者の技量 に左右される。
- Fate/strange Fake Volume 1 - Prologue I: "Archer"
- Fate/strange Fake Volume 1 - Chapter 1: "The War Begins"
- Fate/strange Fake Volume 2 - Chapter 4: Day 1, Before Dawn "A Battle Without Heroic Spirits"
- Fate/strange Fake Volume 2 - Chapter 6: Day 1, Noon "Two Archers and..."
- Fate/strange Fake Volume 3 - Chapter 7: Day 1, Afternoon (1) "The Canon of the Demigods"
- Fate/strange Fake Volume 4 - Chapter 10: Day 2 "Separate Mornings, Separate Pasts I"
- Fate/strange Fake Volume 4 - Chapter 13: Day 2, Night "At Last, a Second, and a Third..."
- Fate/strange Fake Volume 5 - Chapter 14: "Gold and Lions I"
- Fate/strange Fake Volume 5 - Chapter 15: "Gold and Lions II"
- Fate/strange Fake Volume 5 - Bridge Chapter: "One Day, Atop a Building"
- Fate/strange Fake Volume 3 - Chapter 9: Day 1, Evening "A Horse Not Yet Pale; Mud Yet Firm"