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"What are you looking for? More territory? Conditional surrender? Your people won't even make demands, why? How does this war end?"
"It doesn't. Klingons have tasted your blood. Conquer us...or we will never relent.
Katrina Cornwell and L'Rell, 2257[src]

The Federation-Klingon War of 2256-2257 was a conflict fought between the United Federation of Planets and the Klingon Empire.



Following the formation of the Federation in the year 2161, the Klingons saw them as an opponent by the 2220s decade and were close to going to war. However, the two powers did not engage in direct contact with each other for the next century. The first time the Federation and Klingon Empire fought was at Donatu V in 2245. However, it was a stalemate and inconclusive battle. Despite that stalemate, the Klingons were able to launch a raid on Doctari Alpha. In all these encounters, no one in the Federation had seen a Klingon since Captain Jonathan Archer's mission to Qo'noS and the Empire in the 2150s. (TOS movie, novelization & comic adaptation: The Undiscovered Country; DSC episode: "The Vulcan Hello"; ENT episodes: "Broken Bow", "In a Mirror, Darkly, Part II"; TOS episode: "The Trouble with Tribbles")

During this time, T'Kuvma, leader of his house, planned to unite the Empire, the 24 Great houses and it's High Council by focusing their attention on their common enemy: the Federation. Using his flagship, the Sarcophagus, T'Kuvma equipped his house's fleet with cloaking devices. (DSC episode: "The Vulcan Hello")


"(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."
T'Kuvma's speech to his followers[src]

To start this war against the Federation, T'Kuvma and his followers took the Sarcophagus to the edge of Federation space. Once there, they disabled an interstellar relay in order to lure a Starfleet vessel to the area. In May of 2256, the USS Shenzhou under Captain Philippa Georgiou went to investigate the relay. There, the Shenzhou's XO, Commander Michael Burnham, examined the relay, but discovered that it had been disabled by the Klingons. After Burnham accidentally killed the Torchbearer Rejac, T'Kuvma decided to light the Beacon of Kahless and summon the 24 Great Houses' leaders and the High Council. During this time, Burnham attempted to give the Klingons a "Vulcan Hello" by firing on them first. Burnham was then accused of mutiny by Georgiou and sent to the brig. Following the arrival of the Great House's leaders, Georgiou attempted to apologize for the incident. However, T'Kuvma insisted that the Federation was lying, about coming in peace. A Federation fleet under Admiral Brett Anderson arrived to assist with the situation. (DSC episodes: "The Vulcan Hello", "Battle at the Binary Stars")

Opening battles

Main page: Battle of the Binary Stars

Thus, T'Kuvma opened fire on the Shenzhou and both fleets fought each other. Anderson was then able to establish a dialogue with T'Kuvma, but T'Kuvma used this moment to have a cleave ship destroy Anderson's flagship, the USS Europa, and demonstrate his fleet's ability to cloak themselves. More Klingons arrived and destroyed more Starfleet vessels. At this moment, T'Kuvma told the Great House's leaders to return home and proclaim that the Empire would fight united against its enemies. (DSC episodes: "The Vulcan Hello", "Battle at the Binary Stars")

Captain Georgiou and Burnham then attempted to capture T'Kuvma, but Georgiou and T'Kuvma were killed. Despite leaving the Empire without a leader and the Sarcophagus adrift, the Federation and Klingon Empire continued fighting each other for the next six months. By November of that year, over 8,186 Federation citizens had been killed in the war. (DSC episodes: "Battle at the Binary Stars", "Context Is for Kings")

During this time, Captain Gabriel Lorca of USS Buran had been replace by his Terran counterpart from a parallel universe. Posing as his counterpart, Lorca was able to pass himself off as a Starfleet officer. After Lorca survived the self-destruction of the Buran, he was given permission by Starfleet to break its rules in order to win the war. Both Lorca and Starfleet then coerced Lieutenant Paul Stamets' and Straal's research into the USS Discovery's experimental Spore drive. The Discovery was then able to win several victories against the Klingons thanks to the use of a Tardigrade, Ripper.(DSC episodes: "Context Is for Kings", "Choose Your Pain", "The Butcher's Knife Cares Not for the Lamb's Cry")

In November, the Klingons attacked Corvan II's colony and dilithium mines. At the time, Corvan II supplied nearly 40% of the dilithium for Starfleet. However, the Discovery was able to destroy the Klingons' forces. Three weeks later, Discovery used its drive to break the Klingon supply line at Benzar and rout an attack through the Ophiucus system. Starfleet started to build spore drive units in a secret facility on Earth, while directing every ship, colony and starbase to search for more Tardigrades. (DSC episodes: "Choose Your Pain", "Magic to Make the Sanest Man Go Mad")

During this time, Commander Kol of the House of Kor then took command of the Sarcophagus away from Voq and equipped his forces with its cloaking device. Kol then became a general and established a new ruling council. However, in December, House of D'Ghor and Mo'Kai secretly approached Vulcan to discuss a potential alliance with the Federation after they were ousted by Kol. However, Ambassador Sarek sustained wounds in a terrorist attack and Admiral Katrina Cornwell decided to take his place on Cancri IV in the negotiations. However, it was revealed to be a ruse by Kol and the Admiral was captured. More of the Great Houses joined Kol and the USS Gagarin was destroyed. (DSC episodes: "The Butcher's Knife Cares Not for the Lamb's Cry", "Lethe", "Si Vis Pacem, Para Bellum")

Discovery was then sent to Pahvo, so that they could use the Pahvans' crystal transmitter to find the Klingons' cloaked ships. However, the Pahvans transmited a signal to Kol's flagship, the Sarcophagus. The crew of Discovery were then able to board the Sarcophagus, rescue Admiral Cornwell from captivity and plant beacons to penetrate the cloaking device's field. Using the spore drive, Discovery was able to gather enough data to complete an algorithm which would counteract the cloaking technology, and then destroyed the Sarcophagus. Starfleet then asked for the algorithm's information, but Discovery was unable deliver it. When Discovery attempted to use the spore drive to jump to Starbase 46, the Discovery then found itself in the mirror universe. Unbeknownst to Starfleet or the Discovery crew, the commanding officer, Gabriel Lorca did this intentionally in order to return to his universe, trapping the ship and its crew. (DSC episodes: "Into the Forest I Go", "Despite Yourself")


Nine months into the war and well into 2257, the Klingons were divided. Each house were attacking different parts of the Federation. Starfleet also believed that Discovery had been destroyed by the Klingons, but it was actually the ISS Discovery. The Klingons attacked Kelfour VI, Starbase 22, Starbase 12, Starbase 19, Nivalla, Septra, Iridin, and captured Starbase 1.

The USS Discovery then returned to their universe and saw that House D'Ghor had taken Starbase 1. The Klingons were then in position to strike Earth. Thus, the Federation Council were forced adopt Terran Empress, Philippa Georgiou's plan to attack Qo'nos. Thus, Georgiou agreed to pose as her counterpart and lead the Discovery to the Qo'nos' subterranean caverns. In truth, Georgiou was allowed to plant a hydro bomb in a volcano in order to cripple the Klingons. However, Burnham and the Discovery's crew stopped and the hydro bomb's detonator was then given to L'Rell. With this bomb, L'Rell was then able to force the High Council and the Great House to recall their forces and end the war.(DSC episodes: "The War Without, The War Within", "Will You Take My Hand?")

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The Federation and Klingon would be at a stalemate for the next 10 years until 2267. (TOS episode: "Errand of Mercy")



Federation-Klingon Wars
UFP emblem image. Seal of the Federation Starfleet. Federation-Klingon Cold War (23rd century-2293) • Four Years War (2250s) • Federation-Klingon War of 2256-2257Federation-Klingon War of 2267 (2267) • Federation-Klingon War of 2269 (2269) • Federation-Klingon War of 2285 (2285) • Federation-Klingon War of 2372-2373 (2372-2373) • Federation-Klingon War of 2405-2410 (2405-2410) Emblem of the Klingon Empire
Starships in the Federation-Klingon War of 2256-2257
Federation, Starfleet USS DiscoveryUSS KeralaUSS RideUSS SebrovaUSS SiouxUSS Ticonderoga Federation icon image. Starfleet icon image.
Federation losses USS ClarkeUSS BuranUSS DanaUSS EarhartUSS EdisonUSS EuropaUSS GagarinUSS GlennUSS HooverUSS MurocUSS ShranUSS ShenzhouUSS T'Plana-HathUSS Yeager
Klingon Empire, Defense Force L'Rell's battlecruiserSarcophagus Klingon Empire icon image.
Klingon losses Klingon cleave ship

External link

Federation-Klingon War of 2256-2257 article at Memory Alpha, the wiki for canon Star Trek.