When G'Kar was born in early 23rd century, Narn was still under Centauri occupation and so he spent most of his childhood in various bomb shelters. For the first ten years his name wasn't G'Kar, though - he only acquired that name when he was old enough to choose which religion he wanted to follow (he chose G'Quon). In those days G'kar's family lived in G'kamazad, one of the largest cities on Narn. With his mother too ill to escape the city, his father was forced to serve a Centauri family. One day G'Kar's father spilled some hot drink on the mistress of the house and with the tensions running high between the Narn and the Centauri, the Centauri had him killed. The night after his father died, G'Kar ran away and killed his first Centauri.

During the Earth-Minbari war G’Kar dealt weapons to Earth and when Delenn organised a secret peace negotiation between the two warring sides, he accompanied Earth's representatives, acting as a translator (he could speak both English and Minbar). The negotiations failed when Londo Mollari found out about G'Kar's involvement, misinterpreted it as yet another arms deal between the humans and the Narn and ordered a military strike against it. The Minbari representative was killed and G’Kar and the humans, John Sheridan and Stephen Franklin, were taken prisoners by the Minbari. G’Kar was never really in any danger because the Minbari didn't want to involve the Narn into their war, and he was released (as eventually were Sheridan and Franklin, though reluctantly).

In 2253 G'Kar joined Kha'Ri, the council that leads Narn, and a few years later he became the Narn ambassador on Babylon 5. Not long after his arrival to Babylon 5 he was already scheming against the other ambassadors as he took part to a conspiracy that made an attempt on Ambassador Kosh Naranek's life and framed Commander Sinclair for it.

Hostility between the Narn and the Centauri culminated in Londo and G’Kar’s relationship and the two were constantly in each other's throats both literally and metaphorically. The two races were on the brink of another war for a long time, but in 2258 G'Kar began to suspect that the Centauri were getting outside help in their attempts to destroy the Narn. Still, it took a very long time for anyone to believe his claims.

When the Centauri Emperor Turhan visited B5 in 2259, G'Kar tried to assassinate him. Fortunately or not, the Emperor fell ill before he had a chance to act. Unaware of G'Kar's plans Turhan sent him a message apologising for what his people had done to G'Kar's people. There might had been peace between the two races had Londo not at the same time been organising an attack on a Narn outpost. Less than a day later Narn declared a war against the Centauri. The war didn't go well for the Narns and G'Kar soon had to beg help for his people from both the humans and the Minbari - both races denied any military assistance (though in secret Sheridan and Delenn did arrange some humanitarian aid). It was then no surprise that the war ended as it did. The Narns were forced to surrender after the annihilation of their homeplanet. By requesting a sanctuary from Sheridan G'Kar avoided capture and was thus the being the only member of Kha'Ri to survive the Centauri persecution. Even though his ambassadorial status was taken away from him he maintained his status as the leader of B5's Narns and started working actively in the resistance.

G'Kar's hate against the Centauri diminished a bit after he assaulted Londo under the influence of 'dust'. This telepathic drug enabled him to find out all of Londo's secret's, but apparently due to an overdose, he also accidentally 'got lost' in his own mind. Unaware that he was manipulated by Ambassador Kosh, G'Kar saw a vision of his father, a being of light and an old Narn who told him that "some must be sacrificed if all are to be saved". Enlightened by this experience G’Kar didn't resist being arrested and happily served his punishment, using this time of incarceration to write down his thoughts about the war.

When B5 broke away from Earth G’Kar offered Sheridan his support and the help of all the Narn on the station. In return he was accepted into the War Council and finally found out the truth about the Shadow involvement in the Narn-Centauri war. For over a year G’Kar had not left B5, but when Michael Garibaldi disappeared in late 2260, he decided to risk his capture in order to find his friend. Unfortunately he was captured soon after. The Centauri Emperor Cartagia gave G'Kar to Londo as a gift, but still maintained his right to torture the Narn for his own amusement (this included removing G’Kar’s eye). Londo, who was conspiring against Cartagia offered G'Kar a deal - if the Narn helped him to assassinate the emperor, not only G’Kar, but the entire Narn would be free. Both Londo and G'Kar kept their promises.

Even this co-operation didn't remove all the hostilities between Londo and G’Kar. Only after they joined their forces to help Sheridan fight President Clark, did they consider each other if not friends then at least allies. They continued their co-operation when they helped Delenn create the Interstellar Alliance (with the three of them acting as the advisory board for the Alliance).

Alongside his political career G’Kar was pursuing a career as a writer. Not only was he still working on his the book he began while serving time for the assault on Londo, but he also wrote the declaration of principles for the Interstellar Alliance. Still, he felt useless and Delenn assigned him as Londo's bodyguard. At first G’Kar had no desire to act as 'a symbol of co-operation', but in the end he accepted the job and not least because it annoyed the Centauri.

G'Kar's new assignment caused misunderstandings among the Narn - they were afraid that he was going to be killed and so they decided to honour him by 'liberating' the book he had been writing for two years. By the time G'Kar returned from Centauri Prime, thousands of copies were already made and he had become a religious symbol. At first G’Kar was reluctant to accept his new role, but his friend Ta'Lon managed to persuade him into talking to his disciples.

When the Interstellar Alliance discovered evidence that the Centauri were responsible for terrorising Alliance shipping lines, G’Kar stayed on Londo's side believing that he was unaware of his government’s actions. While they were on Centauri Prime the disagreements between the Alliance and the Centauri turned into a war and G’Kar, still a member of the advisory board, was incarcerated. Now it was Londo's turn to stay by G’Kar’s side. The war (which, in fact, had been orchestrated by the Drakh) came to an end when the some of the Alliance worlds, against Sheridan's orders, attacked the Centauri capital. G’Kar too would have been among the casualties had Londo not saved him. Unaware that Londo, who would now be the emperor, had almost literally sold his soul to the Drakh in order to save his world, G’Kar returned to B5 but forgave Londo before leaving.

When returning G’Kar wrongly assumed that his followers would have got tired of him, but in fact the Centauri war had only stirred up their ecstasy. Now they wanted him to return to Narn and lead them. But G'Kar didn't crave power - he had already refused leadership once, right after the liberation of Narn a year earlier. Still, he could stay either; the station was literary filled with Narns on pilgrimage and the Narn government had threatened to boycott the Interstellar Alliance if he didn't come home. To solve his problems once and for all G’Kar decided to buy a ship and just travel around the galaxy visiting new places until he would find a way to get rid of his status as a religious icon without betraying his principles. He also got company of Lyta Alexander who was being deported from the station. Still, there was one more unfortunate incident before he was able to leave the station behind. One of his followers was enraged by his plans to abandon his people and planned to kill him. In a chaos that followed the arrest of another assassin, the Narn tried to shoot G’Kar, but the bullet took down Lise Hampton instead. Shocked by this turn of events G’Kar left B5 immediately, but not before appointing his loyal friend Ta’Lon as the New Ambassador.

During the next few years G'kar continued to work for the Interstellar Alliance. He was especially interested in the situation on Centauri Prime and he often visited there with the help of a changeling net. In 2276 he was caught, however, and remained on the planet keeping company to Londo. A year later, when the Centauri society was on the brink of destruction without even knowing it, the Drakh had G'Kar imprisoned and tortured in order to keep Londo in their leash. G'kar was eventually set free and when he visited Londo for the last time, the powerless and controlled Emperor asked for one favour. He asked G'Kar to kill him, so that Sheridan and Delenn, who were also imprisoned, could escape the planet without the Drakh knowing it. Reluctantly G'Kar agreed, but as he was strangling his friend, the Drakh keeper on Londo's shoulder awoke and took over the Emperor. After a brief struggle both the Narn and the Centauri were killed.