Battle of Cardassia
The Battle of Cardassia (also known as the Invasion of Cardassia) was the final battle of the Dominion War, fought in late 2375. The Federation Alliance, the forces of the United Federation of Planets, the Klingon Empire, and the Romulan Star Empire,  as well as the Cardassian Union launched an invasion with the goal of capturing the Dominion's Alpha Quadrant headquarters on occupied Cardassia Prime. The battle would ultimately lead to the Dominion's unconditional surrender of all forces in the Alpha Quadrant.

The events of the battle were related to concurrent events on Cardassia Prime in the final stages of the Cardassian Rebellion, led by Legate Damar. The sabotage committed by the Cardassian insurgents played an important role in disrupting Dominion communications and support behind the front lines. In reprisal, the Dominion smashed the rebellion before the battle and began systematically punishing the population by launching attacks against civilians, which ultimately led to the Cardassian Union switching sides. Before the battle was over, however, more than 800 million Cardassian civilians would be killed by Dominion genocide, leaving the once-proud capital planet in ruins.

Prelude 
By late 2375, the Dominion's offensives in the Alpha Quadrant had stalled, leaving its forces embroiled in a war of attrition along several fronts. Reinforcements through the Bajoran wormhole had been blocked since the beginning of the war, and the existing industrial infrastructure in Cardassian territory was insufficient to maintain an offensive posture for a prolonged period of time. In addition, the Chin'toka system had been lost to the Federation Alliance in 2374 and more recently Septimus III had been taken by the Klingons, so even Cardassian territory didn't provide a completely secure base of operations. ()

The Dominion's last hope for a quick victory was its alliance with the Breen Confederacy and their energy-dampening weapon, against which the allies initially had no defense. Although the Breen's weapon had a major effect in its first uses, particularly at the Second Battle of Chin'toka, a chance tritium intermix modification on the , intended to compensate for a containment problem, had rendered the ship immune to the weapon prior to the battle at Chin'toka, making it the only Allied ship to survive. However, this modification only worked on Klingon ships, requiring the Klingon Defense Force to hold the line until countermeasures could be developed. This nearly failed when Chancellor Gowron attempted to take the initiative and place General Martok in losing almost impossible to-win battles in order to eliminate him as a political rival. However, after Gowron was killed by Worf and Martok became chancellor, the Klingon forces again held the line.

The Dominion's chance at a quick offensive during this time was lost by the start of Legate Damar's rebellion, which caused massive disruptions behind the lines and forced the Dominion to devote considerable resources to quelling the uprising. By the time Damar's resistance cells were eradicated, the Federation and the Romulans had already developed countermeasures to the Breen weapon, after acquiring an example of the weapon stolen by Damar, with the help of Odo, Elim Garak and former resistance fighter Kira Nerys, effectively negating the biggest tactical advantage that the Dominion had in the war. ()

Apparently becoming disillusioned with the war, and at death's door due to the effects of the morphogenic virus, the Female Changeling ordered Dominion forces to effect a complete withdrawal from all territories held outside Cardassian space. It was hoped that by reverting to pre-war territories, the Dominion would solidify its defense perimeter in which it could rebuild its forces quickly, shorten its supply lines, and survive longer than it would in its current position, which was severely overstretched with the Romulan, Federation, and Klingon fronts to maintain. With less territory to defend, the Dominion could repel any attack and build up its forces for a renewed invasion several years later.

This move could have signaled an end to the war; the withdrawal of all enemy forces from conquered territories was one of the major aims of the war for all allies. However, the Founders seriously miscalculated the allies' resolve to win the war at any cost, assuming that the Federation leadership was too timid to mount an offense, and believing the Alliance would simply try to contain the Dominion in their borders. In addition, Captain Benjamin Sisko and Admiral William Ross recognized the threat of allowing the Dominion to remain in Cardassian space uncontested. Fearing the Dominion would simply rebuild their forces and attack all out once and for all the Alliance came to one conclusion. Therefore, the allies agreed to launch an invasion of Cardassia Prime itself, with the aim of decapitating the Dominion leadership and throwing its hierarchy into chaos. ()

The battle

Phase one: invasion 
Launching their attack fleet from Deep Space 9, the Alliance made a beeline for Cardassia, crossing the distance in approximately one and a half days. The Female Changeling ordered as many ships as possible to meet them, perceiving that the coming battle would be the final, decisive engagement of the war. 

On the allied side, Chancellor Martok prophetically spoke of the allied victory, having brought a barrel of bloodwine, vintage 2309 – the finest, in preparation of the celebration.

As the two enemy fleets made their final approach, the Female Changeling, the Vorta Weyoun, and Breen Thot Pran were inside Dominion Headquarters making final plans for the attack. Noticing that the Dominion Fleet was spread too thin, particularly in the middle of their lines, Weyoun prepared to order the Jem'Hadar to reinforce their position. But suddenly, nearly every Dominion installation on the surface of Cardassia lost power – the Cardassian Liberation Front, led by Legate Damar, had inspired the Cardassian populace to rise up and overthrow their Dominion occupiers. The Dominion fleet was completely cut off from any support or instructions from the surface of Cardassia. 

As the Dominion attempted to regain access to their long range communications, they launched hard and swift punishment for the Cardassians' betrayal. The Female Changeling ordered Jem'Hadar forces to bombard Lakarian City, destroying it utterly and killing two million men, women, and children in a matter of seconds. Weyoun announced to the public that another Cardassian city would be destroyed for each further act of sabotage. However, rather than cowing the Cardassian people back into submission, the opposite effect was achieved and the people began to revolt against their oppressors.

In space, the two fleets bore into each other with abandon, with the battle degenerating into a melee of close-quarters combat. Although the Dominion's lines were spread relatively thinly in the center of their formation, the Dominion forces were able to destroy the Romulan flagship. Captain Sisko marshaled several attack wings to reinforce the Romulan lines, while Ross and Chancellor Martok's forces targeted the Dominion center.

With the battle still raging, the Cardassian fleet – with knowledge of the Dominion's vindictiveness – ultimately switched sides, turning on their Dominion allies in response to the destruction of Lakarian City, much to the benefit of the crew of the . Taking advantage of the sudden chaos amid the enemy forces, and with the help of the Cardassians, the allies were able to punch through the core of the defending Dominion fleet.

Back at Dominion Headquarters, the Dominion command staff finally reestablished communications with their fleet, only to discover that the Cardassian forces had completely turned against them. Furious, the Female Changeling ordered the Dominion and Breen forces to disengage and retreat to Cardassia Prime, proclaiming "there will be no more running." The defending forces withdrew from the battle, leaving the allies victorious. ()

Phase two: final resolution 
The battle was not yet over, however. Captain Sisko and Chancellor Martok convinced Admiral Ross to press their advantage, despite having already lost a third of their forces during the battle. Even with the Dominion's influence restricted to Cardassia Prime itself, its "impressive" ability to rebuild its forces would only prolong the inevitable. Recognizing this, and with the Cardassian ships on their side, the allies chose to press onwards.

On Cardassia, the Female Changeling, suffering from the final stages of the debilitating morphogenic virus, seemed to grow completely frustrated with the Dominion's allies. Angered by the sudden betrayal of the Cardassian fleet, she took to a final solution and ordered the Jem'Hadar to begin exterminating the entire Cardassian population. The Jem'Hadar summarily began executing every civilian they came across, and destroying residences building by building. Among the Cardassians killed was Legate Broca, who tried to reaffirm his loyalty to the Dominion to no effect.

Damar, along with Kira Nerys and Elim Garak, had at one point been captured, but as they stood in the firing line a Cardassian unit gunned down their Jem'Hadar executioners, with the leader, Ekoor, proclaiming "That's for Lakarian City" as the last one fell. Bolstered by the Cardassian volunteers, the three mounted an assault against the Dominion headquarters compound, seeking to capture the Founder alive and force an end to hostilities. With so many of the Jem'Hadar guards sent to destroy the Cardassians, there were only a few left to guard the Founder. Although Damar was tragically killed during the short but sharp fight, the remaining rebels fought their way to the headquarters' briefing room, capturing the Female Changeling and killing the last Weyoun.

In orbit, the allies found thousands of Jem'Hadar and Breen warships, plus thousands of the Cardassian orbital weapon platforms, notably encountered at the first Battle of Chin'toka a year before, waiting for them. Unwilling to turn back, they prepared to launch a three-prong attack on the Dominion's defenses. Federation vessels would attack the platforms and the Romulans and Cardassians would hit the Jem'Hadar forces, while the Klingons would take on the Breen – an attack that was projected to cost up to 40% of their remaining forces, without even accounting for the following ground assault.

As the rebels on the surface tried to convince the Founder to surrender, her chilling plan became clear – by ordering the Jem'Hadar and the Breen to fight to the very last man, she sought to make the allies' victory so costly that it "would taste as bitter as defeat." She hoped to ensure that the Alpha Quadrant powers would never again threaten the Dominion, believing that the Alliance would attack the Gamma Quadrant despite claims that they would not.

Before the final assault began, however, Odo, recently cured of the disease affecting the rest of his race, volunteered to try to convince the Female Changeling to surrender to the allies. By linking with her, Odo managed to cure her of the disease and persuade her to call for an end to the fighting. The Dominion forces in orbit and on the surface stood down and surrendered. The battle – and the war – was suddenly and finally over. ()

Aftermath 

The instrument of surrender, the Treaty of Bajor, was signed at Deep Space 9 only days later. In it, the Dominion agreed to withdraw all of its forces to the Gamma Quadrant. All borders and territorial sovereignty would be returned to their pre-war states. The Female Changeling agreed to stand trial for war crimes committed by the Dominion in exchange for Odo returning to the Great Link to cure the rest of their race of the morphogenic virus. 

Had the Founder not chosen to surrender, the Jem'Hadar and Breen were expected to have fought to the last man. This would have resulted in a costly fleet engagement with a projected loss of an estimated 40% of the Alliance fleet, along with a ground invasion expected to result in many casualties itself. As it was, the battle, and the war itself, was nothing short of a disaster for Cardassia and its people, devastating a huge portion of its surface and killing over 800 million civilians. It was only in avoiding the final assault that more bloodshed was averted. ()

External link

de:Schlacht um Cardassia
fr:Bataille de Cardassia
ja:カーデシアの戦い
nl:Slag om Cardassia
Cardassia, Battle of