T'Kuvma (Klingonese spelling: tIquvma) was a 23rd century Klingon warrior, leader of his house and a follower of the ancient teachings of Kahless. A staunch traditionalist and Klingon nationalist, he was deeply suspicious of the expanding United Federation of Planets, which he regarded as a threat to Klingon culture and identity. He believed in unifying the feuding Klingon Great Houses against the Federation. (DIS: "The Vulcan Hello")
By 2256, T'Kuvma had assembled a like-minded group of Klingons and provoked a confrontation in a binary star system between several of the Great Houses and a fleet of Starfleet vessels. In the ensuing Battle of the Binary Stars, T'Kuvma was killed by Commander Michael Burnham, but he had succeeded in provoking a Federation-Klingon war and unifying the Great Houses against the Federation. (DIS: "Battle at the Binary Stars")
When he was young, T'Kuvma rediscovered the Sarcophagus, an old ship that had belonged to his father and been abandoned after his death. The derelict was used as a playground for other Klingon children, who attacked T'Kuvma when he tried to chase them away. (DIS: "Battle at the Binary Stars")
Uniting the Klingon Empire
T'Kuvma believed the Federation's claim that "we come in peace" to be a lie and saw it as a threat to Klingon identity and culture. He sought to use the threat of the Federation as a means to unify the twenty-four Great Houses of the Klingon Empire by focusing their attention on a common enemy. T'Kuvma cast his movement as messianic and millenarist: he acquired the Beacon of Kahless, an ancient artifact that, according to prophecy, would unite the Great Houses when lit. He assembled a number of Klingons under his leadership. Unlike other Klingon Houses, T'Kuvma accepted outcasts such as the albino Voq. (DIS: "The Vulcan Hello")
Seeking to provoke a general confrontation with the Federation, in 2256 he placed the Beacon of Kahless in a binary star system near the edge of Federation space, and disabled the interstellar relay there to attract the attention of Starfleet. The USS Shenzhou was dispatched to investigate, and the first officer, Commander Michael Burnham, made a space walk to investigate the Beacon. While there she was attacked by T'Kuvma's Torchbearer, Rejac, whom she killed in self-defense. T'Kuvma proclaimed Rejac a martyr and named Voq the new Torchbearer. (DIS: "The Vulcan Hello")
Battle of the Binary Stars
Giving Voq the honor of activating the Beacon, T'Kuvma ignored an offer of negotiations from Captain Philippa Georgiou and declared it an example of Federation duplicity. Several members of the Klingon High Council arrived in the system with their ships in response to the signal from the Beacon, and T'Kuvma collectively addressed them as Starfleet reinforcements arrived to support the Shenzhou. Rallying a number of the Great Houses to his cause, T'Kuvma launched an attack on the gathered Federation vessels, beginning the Battle of the Binary Stars. (DIS: "Battle at the Binary Stars")
After a significant number of casualties on both sides, the senior Starfleet commander, Admiral Brett Anderson, called for a ceasefire, T'Kuvma accepted, and asked the Human to prepare for the arrival of his envoy. However, T'Kuvma instead used the truce to ordered one of his cloaked vessels to ram the admiral's ship, the USS Europa, leading to its destruction. (DIS: "Battle at the Binary Stars")
After declaring victory over the Starfleet vessels, T'Kuvma instructed the High Council members to return to Qo'noS to spread news of the united Empire, and was proclaimed to be "T'Kuvma the Unforgettable" by his supporters L'Rell and Voq. (DIS: "Battle at the Binary Stars") "The Unforgettable" was the most common epithet used in reference to Kahless. (TOS: "The Savage Curtain")
Remaining behind to collect and sanctify the Klingon dead, the Sarcophagus was suddenly disabled by the apparently-crippled USS Shenzhou. Captain Georgiou and Commander Burnham beamed aboard, seeking to capture T'Kuvma and demoralize the Klingon war effort. Engaging Georgiou in hand-to-hand combat, T'Kuvma slew the Starfleet captain, before being shot in the back by a phaser blast from Burnham, set to kill. (DIS: "Battle at the Binary Stars")
Burnham escaped the Sarcophagus and was subsequently court martialled for the events at the Binary Stars. The dying T'Kuvma was told by Voq that he would be remembered forever by all Klingons, and that his death would be the cause to unite the Empire. (DIS: "Battle at the Binary Stars")
T'Kuvma had indeed unified the Klingon Empire against the Federation, however his followers were largely abandoned by the rest of the empire. The crippled Sarcophagus was left adrift in the binary star system for several months after his death, with only Voq, L'Rell and a handful of other Klingons still aboard. Voq was subsequently overthrown by Kol of the House of Kor, who repaired the vessel and took it for his own to lead the war against the Federation. (DIS: "The Butcher's Knife Cares Not for the Lamb's Cry")
Voq and L'Rell remained loyal to T'Kuvma's memory: Voq underwent extreme surgery to pass as the Starfleet Lieutenant Ash Tyler while L'Rell allowed herself to be captured, in order to infiltrate the USS Discovery and find T'Kuvma's killer, Michael Burnham. However, after the emergence of Voq's personality went awry, L'Rell was forced to euthanize Voq by merging his and Tyler's personalities. (DIS: "Choose Your Pain", "Despite Yourself", "The Wolf Inside", "Vaulting Ambition")
After the Battle at Pahvo, in which the Sarcophagus had been destroyed, the Empire became fractured once again and the Great Houses began competing for and indiscriminately destroying Federation assets – precisely the opposite of what T'Kuvma had hoped to achieve. This resulted in such devastating Federation losses that Starfleet resorted to accepting a proposal by the mirror universe's Philippa Georgiou to devastate Qo'noS using a hydro bomb. In order to end the war and prevent this act of genocide, Burnham prevented Georgiou from detonating the bomb and handed the detonator to L'Rell, who proceeded to assume leadership of the Klingon High Council, enact a cease fire, and then continue T'Kuvma's work to unite the Empire. (DIS: "The War Without, The War Within", "Will You Take My Hand?")
"(in Klingonese) They are coming. Atom by atom, they will coil around us and take all that we are. There is one way to confront this threat. By reuniting the twenty-four warring houses of our own empire. We have forgotten the Unforgettable, the last to unify our tribes: Kahless. Together, under one creed, remain Klingon! That is why we light our beacon this day. To assemble our people. To lock arms against those whose fatal greeting is... (in English) we come in peace."
"(in Klingonese) Witness our brother, our torchbearer, killed by the Federation interloper on our sacred beacon. I see you as you see the end. Our torchbearer honors us... first to die in our crusade of self-preservation.... Our ancestors welcome our fallen brother, Rejac, to their Black Fleet. They fight with us, as we fight against our enemy. Remain Klingon!"
"(in Klingonese) I recognize you as one who has lived his life on the outside and yearns to be part of something bigger than himself. Some may see the color of your skin as nature's mistake. I call it a mirror... for I see myself in you."
"(in Klingonese) The honor of Torchbearer is yours."
"(in Klingonese) 'My presence.' 'My voyage.' 'My time.' No one speaks of 'my duty' or 'my honor.'"
"(in Klingonese) Show respect, T'Kuvma. You are nothing. You have not earned a seat on this council."
"(in Klingonese) And yet, I am the one who leads the way to our Empire's resurrection."
"'(in Klingonese) But there is no honor without unity. There is no home for any of us, unless it is shared by all."
"'(in Klingonese) My house is open to all. Including those discarded by you, Kol. But my house is bonded by a single doctrine: Remain Klingon."
"(in Klingonese) We have become complacent in the time since we last battled the Federation at Donatu V. Our purity is a threat to them. They wish to drag us into the muck, where Humans, Vulcans, Tellarites, and filthy Andorians mix."
- - T'Kuvma to the other Klingon leaders on the idealism of the Federation (DIS: "Battle at the Binary Stars")
"(in Klingonese) Great leaders, everything I say will come to pass. Look to the stars. Our destiny has arrived!"
- - T'Kuvma, commending his own reliability and announcing the arrival of a Federation fleet (DIS: "Battle at the Binary Stars")
"No! They do not! They come to destroy our individuality. Shall we rise up together and give them the fight they deserve?"
- - T'Kuvma on what he thinks of Starfleet's "We come in peace" message (DIS: "Battle at the Binary Stars")
"Admiral, I am T'Kuvma. I am pleased you are here. We have been waiting for someone worthy of our attention. Your offer of a ceasefire is accepted."
"(in Klingonese) Lest anyone doubt that I can render my own vessels invisible."
"(in Klingonese) We have suffered losses... but the Federation has suffered far more. Leaders, return to Qo'noS. Declare far and wide that the Klingon race fights as a united Empire once again!"
"Members of the Federation, what you call your most remote borders I call too close to Klingon territory. You only live now to serve as witnesses of Klingon supremacy, to be my herald. We do not desire to know you. But you will know our great houses, standing as one under Kahless, reborn in me, T'Kuvma."
"(in Klingonese) A warrior who dies in his sleep is no more than flesh and bone. A warrior who perishes honorably in battle is blessed. A hero's demise brings pride for a life given in defense of our race and comfort in the knowledge that new life awaits in Sto-Vo-Kor. Join your vaunted comrades, brothers and sisters, for you are not alone and stand watch among the Black Fleet forever."
"(In Klingonese) Whom do we seek?"
"How do we find him?"
"Give us light to see."
"Will he hide from us always?"
Obi compared his character to Moses, noting, "He's an outsider and he has a spiritual moment where he encounters Kahless [...] and he is given a message [...] He's like the runt of the litter, and he transforms into this leader, with a purpose." (AT: "O Discovery, Where Art Thou?")
At first, Chris Obi was very worried about how he would manage to learn all of T'Kuvma's Klingon dialogue. However, he managed to overcome that fear with the help of Burnham actress Sonequa Martin-Green, as well as a speaker of Klingonese who prepared a tape recording for the project, and two voice coaches who Obi described as "amazing." He recalled, "I would go away and listen to the sounds and come back with my version of it." (AT: "O Discovery, Where Art Thou?")
Chris Obi was highly pleased to be able to portray T'Kuvma, as he found the character to be very consistent. "I'm beyond blessed to be given a character that you don't go, 'Ooh, God. He's going to say that, even in Klingon.' Know what I mean?" he remarked. "That's where the connection comes. Every time I speak a line, I believe the character is truly saying these lines, and it fits. You know?" (AT: "O Discovery, Where Art Thou?")
T'Kuvma was featured in a deleted scene extension from "The Vulcan Hello", in which, after lighting his bat'leth on fire in an alcove on the bridge of his ship, he turned around, said something to L'Rell, then walked past her. (AT: "O Discovery, Where Art Thou?")
T'Kuvma's backstory is explored in the IDW comics series Star Trek: Discovery - The Light of Kahless. T'Kuvma's sister, J'Ula, is the main antagonist of the "Age of Discovery" expansion to Star Trek Online.