Attack on the Resistance fleet

The First Order launched an attack on the Resistance fleet during the First Order–Resistance war following the evacuation of D'Qar. The First Order managed to track the Resistance fleet through hyperspace, forcing the Resistance to flee in search of a way of escape before their fuel supplies ran out within 18 hours.

Prelude
Quickly after the Battle of Starkiller Base and its destruction the First Order mounted an attack on the Resistance base on D'Qar. The First Order had learned of the location and had planned on destroying it with the weapon, however Starkiller Base was destroyed. The Resistance managed to flee D'Qar before their base was bombed by the Mandator IV-class Siege Dreadnought Fulminatrix. Before this, however, Commander Poe Dameron destroyed the defense turrets on the top of the ship, leading to him ordering a bombing run that successfully destroyed the dreadnought, but at the cost of the Resistance's entire bombing fleet. This caused General Leia Organa to demote him to Captain after the Resistance jumped to hyperspace.

Immediately after the loss of the dreadnought, Supreme Leader Snoke contacted General Armitage Hux in anger about the loss. However, Hux assured Snoke that they had still cornered the Resistance, and went to the Supreme Leader's Star Dreadnought Supremacy to reveal their ability to track the Resistance fleet through hyperspace. As the Supremacy-led fleet pursued the Resistance through hyperspace, Snoke met with his apprentice Kylo Ren, enraged at Ren's internal conflict and his loss to the unknown Force user Rey. After their meeting, Ren told the First Order troops to prepare his fighter.

The chase begins
When the Resistance jumped out of hyperspace, they were immediately confronted by the First Order fleet. Caught completely off-guard, the Vigil was fired on and destroyed by the massive ship before it could either get out of range or raise its deflector shields. Knowing that the First Order would just pursue them if they went to hyperspace again, which would deplete their fuel levels, the Resistance strengthened their rear shields and piloted their fleet out of the First Order's range as their fighter pilots prepared to go out and attack. However, Ren and three other pilots took TIE Fighters to take out the Resistance's command ship Raddus. One of the fighters was quickly taken out, but Ren blew up the hangar, destroying the Resistance's starfighters and the other two TIEs, via Lieutenant Poldin LeHuse, blew up the bridge, killing all the Resistance officers on it except for Organa. However, LeHuse and the other TIE/sf fighter were in turn shot down by the Ninka and Hux commanded Ren to return to the Supremacy, since the Resistance fleet was too far away for the First Order fleet to back up its fighter ships.

Organa was placed on life support, and Vice Admiral Amilyn Holdo was placed in command of the Resistance fleet. Dameron suggested that they come up with a strategy to attack the First Order fleet, but she was intent on maintaining their current course of action. Meanwhile, Finn was caught trying to desert the Resistance by maintenance worker Rose Tico and thrown into the brig. However, after revealing his knowledge of the Supremacy workings, Finn and Tico got the idea to disable the First Order's hyperspace tracking capability. They told Dameron about this, and they contacted Maz Kanata, who was too busy to help them but knew a codebreaker who could get them into the Supremacy who resided on Canto Bight on the planet Cantonica. Finn and Tico took a Resistance transport pod to find the codebreaker.

On the Supremacy, Snoke formed a connection between Ren and Rey in order to discover the location of the last Jedi Luke Skywalker. Rey decided to come to the Supremacy to see Ren, believing she could convert him to the light side of the Force.

The Resistance's counterattack
The three remaining Resistance ships continued to outrun the larger First Order vessels, their speed and strong shields able to keep them just out of range enough for the Supremacy turbolasers to be ineffective. However, their fuel reserves were dangerously low and one by one the other ships ran out of fuel and were immediately destroyed once they had drifted into range of the enemy. The Nebulon-C escort frigate Anodyne, which was also their medical frigate, was the first to run dry and was shortly followed by the Free Virgillia-class Bunkerbuster cruiser Ninka, though both their crews successfully managed to evacuate their doomed craft before their destruction. This left the Raddus as the sole cruiser, carrying what now amounted to the entire Resistance. Vice Admiral Holdo revealed her plan to evacuate the Resistance on small transports. Believing the action to be too risky and foolish, Dameron incited a mutiny and had the leadership held at gunpoint by at least three Resistance members as he went to contact Finn and Tico. The two had found a codebreaker named DJ who successfully got them onto the Supremacy.

Meanwhile, Rey arrived at the Supremacy, but Ren had her arrested. She was taken to Snoke, who tortured her to discover Skywalker's location before ordering Ren to kill her. However, Ren instead killed Snoke by using the Force to cleave him in two with Rey's lightsaber. Snoke's Elite Praetorian Guard sprang into action to avenge the Supreme Leader, but were all killed by the two Force-wielders. Ren then offered Rey the chance to rule the galaxy with him. Rey refused, and the two battled over Rey's lightsaber, which eventually snapped in half and knocked Ren out. Rey escaped on Snoke's escape ship, and Ren woke up right as Hux was about to assassinate him. Ren then declared himself the new Supreme Leader.

Aboard the Raddus, Holdo fought back against Dameron's mutiny as she and her allies stunned his allies. Meanwhile, Finn, Tico, DJ, and BB-8 infiltrated the Supremacy and got into the room where they could disable the tracker. However, BB-9E had found the group out earlier, calling in reinforcements, causing them to be confronted by Captain Phasma and her troops. As Dameron heard about the capture, General Organa broke into the room he locked himself in and stunned him, returning him to Holdo as the Resistance fighters prepared to evacuate the Raddus. However, Holdo stayed onboard to confront the First Order in an act of self-sacrifice, and when Dameron came to, Organa revealed that they were nearing an old rebel base on the planet Crait and that Holdo knew the First Order would be less likely to spot their smaller escape ships. However, after being caught by Phasma's troops, DJ told the First Order this plan, which he had overheard Finn and Tico mention, in exchange for money. The Supremacy shot at the unprotected escape vessels with turbolaser batteries, destroying all but six of them. They saw that the Raddus was preparing to jump to hyperspace, but believed the cruiser was deserting the Resistance. Once he realized the ship was turning towards the Supremacy, a frantic Hux ordered to fire all cannons on the Raddus, but too late. Holdo then jumped into hyperspace, shearing the massive ship in half and completely destroying a considerable number of other Star Destroyers on escort duty or being repaired on one of the lower hangars.

On the Supremacy, Finn and Tico were about to be executed when the sudden destruction of the ship sent everyone into chaos. The duo freed themselves and attempted to make for a nearby shuttle, only for Phasma and her stormtroopers to emerge from the flames and begin firing on them. Suddenly, an AT-ST started firing on the latter, revealed to be piloted by BB-8. In the chaos, Finn engaged Phasma with a Z6 riot control baton, and was initially overpowered, but managed to hit Phasma with a surprise attack before she fell into a fiery pit. They then hijacked a shuttle and escaped, heading toward the Resistance on Crait.

Aftermath
Hux eventually made his way to Snoke's throne room, and discovered Ren unconscious and Snoke cleaved in half. Hux initially considered taking the opportunity to shoot Ren, although Ren regaining consciousness forced him to put away his concealed blaster and abandon that plan. Ren then lied by claiming Rey killed Snoke and tried to assume command of the First Order, but Hux refused to either acknowledge Ren as Supreme Leader or grant him command of his troops. However, Ren proceeded to implement a Force choke on Hux in return, causing the latter to ultimately "acknowledge" Ren's promotion to Supreme Leader. The newly-made Supreme Leader Ren then commanded the First Order's remaining forces onto Crait, where the assault would resume on land.

Appearances

 * The Last Jedi: Bomber Command
 * Star Wars: Episode VIII The Last Jedi
 * Star Wars: The Last Jedi: Expanded Edition
 * The Last Jedi: Rose and Finn's Secret Mission

Non-canon appearances

 * Star Wars: Droid Repair Bay