First Battle of Deep Space 9 The First Battle of Deep Space 9 was the prelude to the of 2372 and 2373 . In early 2372 , a Klingon task force led by Chancellor Gowron and General launched an attack on the Federation space station of Deep Space 9 , in an attempt to force Captain Benjamin Sisko to relinquish the Cardassian Detapa Council members under his protection . The Klingons had under - estimated the station ' s defenses , and were unable to take the station before the arrival of Starfleet reinforcements . Faced with the prospect of considerable losses , a war on two fronts , and the looming threat of the Dominion , Gowron ordered his forces to withdraw . Prelude . After the Battle of the Omarion Nebula in 2371 , the Cardassian Union was in a state of turmoil . For centuries , the Obsidian Order had kept an iron grip on all levels of Cardassian society , keeping the status quo firmly in place . With the Obsidian Order decimated by the Jem ' Hadar , the Cardassian Underground had finally been able to make headway against the oppressive rule of the Central Command . Faced with growing unrest and civil uprisings , the Central Command sealed the borders of the Cardassian Union to focus their attention on the rebellion . Despite their efforts , early in 2372 a popular revolt overthrew the Central Command and restored the power of the civilian Detapa Council . ( ) Meanwhile , the Klingon Empire had been infiltrated by a Founder , masquerading as General Martok . This Founder , taking advantage of the paranoia effected by the strong possibility of Changeling infiltration , misled the Klingon High Council into concluding the Cardassian uprising could have succeeded only with Dominion assistance – and , with ironic mendacity , he proclaimed the Detapa Council had been replaced by Founders . The Changeling advocated for a Klingon invasion of the Cardassian Union to neutralize the " Dominion threat " . His proposal came at a time when many Klingons believed that decades of peace had led them astray and weakened the Empire . As such , the invasion plans were eagerly embraced by Klingons hoping for a return to the gloried old ways of war and conquest . ( ) When preparations were complete , a Klingon task force of over twenty warships , led by the flagship , arrived at Deep Space 9 , ostensibly to aid the Federation forces guarding the wormhole . Once their true purpose was discovered , Captain Benjamin Sisko urged Martok to reconsider their plans . Disregarding Starfleet ' s warnings , the Klingon fleet proceeded into Cardassian space , commencing the Klingon - Cardassian War . Bound by their alliance , the Federation could do nothing to interfere , although Sisko " unofficially " sent an advance warning to the Cardassians through Elim Garak . A few days later , the Federation Council condemned the Klingon invasion . Outraged that his ally had refused to support him in " defending the Alpha Quadrant " from the Dominion , Gowron withdrew from the Khitomer Accords and broke off all diplomatic contact . ( ) Flight from Cardassian space . Although the Cardassian fleet mobilized in time thanks to Garak ' s warning , the speed and magnitude of the Klingon advance broke through their lines a short time after the invasion began . The Klingon invasion rapidly progressed to the point of the fleet being only 52 hours from Cardassia Prime itself . Standard Klingon procedure for the invasion of the planet would have been to execute the Detapa Council and install an Imperial Overseer , which would effectively end the Cardassian Union . To prevent this from happening , Sisko contacted Gul Dukat , the new chief military advisor to the Detapa Council , and advised him to evacuate the Council to Deep Space 9 . Dukat agreed , and left Cardassia with the Council members aboard the cruiser " Prakesh " . At the same time , Sisko took the into Cardassian space to rendezvous with Dukat , using its cloaking device to hide from the Klingon forces ( in violation of the terms of its loan from the Romulan s ) . When they arrived they found that the " Prakesh " had been intercepted by three Birds - of - Prey , and was under heavy fire . The Klingons ignored Sisko ' s order to stand down , and opened fire on the " Defiant " . With those shots , two decades of peaceful co - existence came to an abrupt end . Amid the fighting , Dukat managed to contact Sisko and informed him that while he and the Council members were alive , the " Prakesh " had already lost all engine , weapon and shield power , and was in grave danger of suffering a warp core breach . The " Defiant " engaged the Birds - of - Prey , buying time for the stricken " Prakesh " while a attack cruiser entered the battle . Using a modified tractor beam to deflect some of the cruiser ' s fire , the " Defiant " lowered its shields long enough to transport the Detapa Council members aboard . The " Prakesh " exploded shortly afterwards as the " Defiant " headed back for Deep Space 9 at maximum warp , the two remaining Klingon warships in close pursuit . With this development , a Klingon force returned from Cardassian territory and headed to the Bajoran system . Aboard the " Defiant " , Doctor Julian Bashir administered blood screening s of the Council members and verified that they had , in fact , not been replaced by Founders . ( ) The Battle . When the " Defiant " reached Deep Space 9 , they found several dozen Klingon warships in an attack formation waiting for them beyond the station ' s shield perimeter . The Bird - of - Prey and the attack cruiser which had pursued the " Defiant " all the way from Cardassian space , joined the Klingon fleet . Gowron and Martok , aboard the " Negh ' Var " , sent an ultimatum to Sisko : surrender the Council members , or have them taken by force . Sisko refused , informing them of the results of the blood screenings . Not surprisingly , the fact that the Council members were not Changelings was irrelevant to Gowron , who asserted that the Alpha Quadrant would be safer with the Klingons in control of Cardassia . Sisko gave a last warning , informing Gowron that over the past year , the station had been receiving state - of - the - art tactical upgrades due to the constant threat of Dominion attack . These upgrades included the installation of numerous new torpedo launcher s , phaser emitters , and shield generators , as well as a stockpile of five thousand photon torpedo es . Gowron scoffed at this threat and ordered his forces to advance , announcing " " CHEGH - chew jaj - VAM jaj - KAK " " – " Today is a good day to die . " The first wave of Klingon ships opened fire on the station , moving to surround it on all sides . The station ' s weapons returned fire , destroying eight Klingon warships in the opening volley and heavily damaging several more . Undeterred , the Klingon forces pressed on their attack . Realizing the futility of additional negotiations with the Klingons , Sisko ordered the station to fire at will . Surprised but undaunted by the station ' s upgraded defenses , Martok ordered the " Negh ' Var " and several support cruisers to concentrate their fire on the station ' s shield generator s . The " Negh ' Var " s heavy disruptor cannon s scored several direct hits , disabling two of the generators and opening a gap in the station ' s shields . Seizing this opportunity , Klingon boarding parties began materializing in the operations center , Promenade , habitat ring , and lower pylon 3 . Small - scale firefights and hand - to - hand combat erupted throughout the station , although civilian casualties were minimal as Sisko had evacuated non - essential personnel to the emergency shelters prior to the battle . The Klingon forces additionally found themselves hindered by force field s erected between all major access points of the station . After the command crew repelled the Klingon boarding parties in Ops , Chief Miles O ' Brien managed to restore Deep Space 9 ' s shields and prevent additional Klingon troops from reinforcing their positions on the station . In the meantime , Odo and his security forces had managed to contain the Klingon troops in the habitat ring , Promenade and lower pylon 3 , though Odo himself was unsure how long they could continue to do so . As the Federation personnel in Ops returned to their posts , another wave of Klingon ships was detected entering sensor range . However , a Starfleet relief force of six starships , consisting of the , two starships , one , and two more starships led by Admiral Hastur aboard the " Venture " , also entered sensor range . Realizing that the Federation relief force would arrive at the station before the Klingon reinforcements , Sisko contacted Gowron again , hoping that the chancellor would see how mutually destructive continuing his attack could become . Martok insisted that the Klingons could still prevail , but Sisko and Worf both warned him that continuing his assault would result in the Klingon Empire entering a protracted , all - out war with both the Cardassians and the Federation , which would only serve to weaken them all and pave the way for the Dominion conquest . Gowron recognized the truth of the Starfleet officers ' argument and ordered the Klingon fleet to stand down and withdraw . ( ) Aftermath . The battle at Deep Space 9 ended indecisively , as even though the Klingons had failed to capture Deep Space 9 or the Detapa Council , their offensive against the Cardassians continued . After the battle , the Detapa Council was safely returned to Cardassia Prime , though their rule would be short . Less than two years later , the devastating war with the Klingons would lead Dukat into delivering the Cardassians into the hands of an even more oppressive power than the Central Command , the Dominion . ( ) For the Federation , an all - out war with the Klingons had been averted , but the alliance that had unified the two powers in friendship for decades was lost . The ensuing low - level Federation - Klingon conflict would escalate into open warfare in late 2372 ; it would end with a cease fire several months later , after Martok was exposed as a changeling , but only after mounting casualties on both sides . Beginning with the Battle of Deep Space 9 , the Founders had nearly succeeded in their goal of irreparably destroying the Federation - Klingon alliance , the only power which could have stood against a Dominion invasion . Fortunately for the Alpha and Beta Quadrant s , the two powers were able to reconcile in time , and turn their attention back towards the Dominion , but not until after the loss of a great many lives . ( )