|“||Think back. At one time, I firmly believed in Deikun's revolution. But democracy turned into uncontrolled corruption. Population grew unchecked, devouring resources heedlessly. Through it's greedy excesses, the so-called noble human race has overstepped it's limits. Its weaknesses have brought it to the brink of extinction, and now the way must be cleared for the coming of the Newtypes and the new world order. This cannibalistic war was caused by Federation weakness. Weakness leads to extinction. And then, I'll make the world fit for a new human race.||”|
Personality & Character
|“||For mankind to progress, a cleansing of the population has been long overdue.||”|
—Gihren's lack of empathy made apparent. 
Skills & Abilities
Granted a high IQ (Intelligence Quotient) of 240, Gihren is a highly gifted and well educated person. He is also a gifted orator, able to rally the people of Zeon after the death of his brother Garma.
He served as aide to his father Degwin and exercised his cunning as director of the Zeon Party's political department. While maintaining Deikun as their public face, Gihren steadily maneuvered to place his father Degwin, the vice chairman, at the center of political power. When the Autonomous Republic of Munzo later became the Autonomous Republic of Zeon, Gihren served as director of both the political and national campaign departments. When it became the Principality of Zeon, Gihren rose to the position of supreme commander. Over the years Gihren's influence continued to grow and by the time of the One Year War, he had already managed to take most of Zeon's political and military power from his father, while isolating him more from the public, thus making himself the real dictator of Zeon.
One Year War
One of the heads of the Principality of Zeon, Gihren is the oldest son of Degwin Sodo Zabi, the ruler of Zeon and the instigator of the war with Earth. With the death of Degwin's favorite son Garma Zabi in battle, Degwin withdraws from day to day duties as Zeon's leader which effectively made Gihren the leader of Zeon in all but name. This was most evident in the speech Gihren gave at Garma's state funeral. This speech was notable for possibly being the debut of the trademark salute "Sieg Zeon!" (literally translated as "Victory [to] Zeon!"). Giren was gifted with a high IQ (240) and ingenious oratory abilities. He and his sister Kycilia Zabi were constantly at odds with each other as both had similar political goals but different methods.
Although Gihren was successful in reducing his father's role to that of a figurehead ruler (even long before Garma's death), he must still endure Degwin's criticism and scorn. Degwin saw Gihren as little more than an updated version of historical dictator Adolf Hitler (a role that Gihren was all too happy to take to heart).
Gihren led his troops into battle and even built the Solar Ray colony laser, which he used against his own father and the Earth Federation's leader, General Revil. During the Battle of A Baoa Qu, Gihren was watching the battle in the fortress when Kycilia Zabi approached him, telling him that she knows that he assassinated their father. In Gihren's defense, he said it was too late to seek peace terms, before Kycilia put a gun to the back of his head and shot him in execution style, avenging Degwin and becoming the Head of Zeon.
Mobile Suit Gundam The Plot to Assassinate Gihren
Comparisons to Hitler
Gihren's own father compared him to Hitler, which may not be completely inaccurate. Like Hitler, Gihren appeared to believe in a 'survival of the fittest' mentality and that the "Superior Race" should rule over the inferior ones (the superior race being Spacenoids from Side 3 and the inferior the Earthnoids). He also shared Hitler's gift for oratory and manipulation, taking the reins of power from his father behind the scenes the way Hitler did with the German president of his day, Paul von Hindenburg. Gihren even adopted the Nazi salute for himself ("Sieg Heil", meaning "Hail [to] victory", became "Sieg Zeon", meaning "Victory [to] Zeon").
Unluckily for Gihren, he also had a number of Hitler's personality flaws, such as an over-reliance on miracle weapons to turn the tide against numerically superior foes. By this logic, the assorted super weapons such as the MA-08 Big Zam and Apsalus Project Mobile Armors can be seen as analogies of the V1 and V2 rocket-bombs used by the Third Reich. Like Hitler, he also greatly overestimated the capability of his forces. This was shown during the final battle of the One Year War, when despite his claims of superiority his forces were overcome by those of the Federation.
In an effort to circumvent the Antarctic treaty (forbidding nuclear, biological, and chemical weapons and colony drops on Earth), Gihren's most ambitious project was the Solar Ray cannon. This consisted of a hollowed-out colony cylinder rebuilt into a giant carbon dioxide laser with the ability to destroy entire fleets. Gihren learned that Degwin, tired of the war, decided to take his personal fleet to a designated area in space where he would meet the fleet of Earth Federation representative General Revil and discuss peace negotiations. Gihren arranged for an accidental firing of the Solar Ray which destroyed Degwin and Revill's entire fleet. However, this may have cost Gihren one of his tactical advantages, as the premature firing burned the laser out.
Kycilia, eventually learning that the death of her father was no mere accident, personally executes Gihren for the crime of patricide. As a result, she takes over during Battle of A Baoa Qu. This resulted in many Gihren loyalists withdrawing from the battlefield, which ultimately contributes to Zeon's disastrous defeat at A Baoa Qu.
Gihren Zabi's Famous "Sieg Zeon!" Speech
-The following is taken from Book#1 of the Mobile Suit Gundam novelization by Yoshiyuki Tomino.
We have lost a hero to our glorious and noble cause, but does this foreshadow our defeat? No. It is a new beginning. Compared to Earth Federation the national resources of Zeon are less than one thirtieth of theirs. Despite this major difference, how is it that we have been able to fight the fight for so long? It is because our goal in this war is a righteous one. It’s been over fifty years since the elite of Earth, consumed by greed took control of the Earth Federation. We want our freedom. Never forget the times when the Federation has trampled us! We, the Principality of Zeon, have had a long and arduous struggle to achieve freedom for all citizens of our great nation. Our fight is sacred, our cause divine. My beloved brother, Garma Zabi, was sacrificed. Why? The war is at a stalemate. Perhaps many of you have become complacent. Such a lack of compassion is ---.
The Earth Federation has polluted our most cherished planet for their own greed. We must send them a message, but not composed of words. We have wasted too much time with words. We need action now. The earthside elite must be taught a strong lesson for their evil corruption. This is only the beginning of our war. We have been putting more and more money into our efforts towards making our military stronger than ever. The Earth Federation has done the same.
Many of your fathers and brothers have perished valiantly in the face of a contemptible enemy. We must never forget what the Federation has done to our people! My brother, Garma Zabi, has shown us these virtues through our own valiant sacrifice. By focusing our anger and sorrow, we are finally in a position where victory is within our grasp, and once again, our most cherished nation will flourish. Victory is the greatest tribute we can pay those who sacrifice their lives for us! Rise, our people, Rise! Take your sorrow, and turn it into anger! Zeon thirsts for the strength of its people! SIEG ZEON!
- Glemy Toto from Mobile Suit Gundam ZZ claimed to be Gihren's genetically engineered clone.
- Gihren's private secretary, Cecilia Irene, is rumored to be his mistress.
- In Tomino's original storyline of Mobile Suit Gundam, Gihren was going to be killed in a gun fight with Amuro Ray.
- In Mobile Suit Gundam: Awakening, Escalation, Confrontation, Gihren is still killed by Kycilia, however, he is killed by a handheld beam rifle to his groin.
- In Mobile Suit Gundam Gihren’s Greed, it's possible for Zeon player to avoid committing most of Gihren's atrocity. Should player archive victory by doing so, Gihren will become a heroic figure who bring golden age to humanity.