|[...] Fort Slava defends the high ground overlooking the naval station. It's impossible to attack the station without control of the fort.|
|— Gabi Braun explains Fort Slava's strategic importance|
Fort Slava (スラバ要塞 Suraba-yōsai?) was a fortress of the Mid-East Allied Forces near the coast of the continental mainland. After the Marley Mid-East War, Marley annexed the fortress and the naval port where the capital fleet of the Alliance was stationed. It was heavily fortified with anti-Titan artillery.
Fort Slava is a fortress atop a high hill that is surrounded by two walls, the low outer wall armed with machine gun bunkers and the high inner wall armed with anti-Titan artillery units, a devastating weapon that can kill a Titan of any variety in one shot. Its position overlooking the harbor allows those within to spot enemies from a distance, preventing the possibility of a sneak attack. There are three interconnected railway tracks that encompass the fort between the walls, with various tracks leading back within the fort. These tracks carry an armored train equipped with particularly deadly anti-Titan artillery.
During the battle of Fort Slava at the climax of the Marley Mid-East War, the Warrior candidates dig trenches in the landscape all around the fortress beyond the outer wall, allowing for soldiers to attack the Allied defenses from a covered position. The battle significantly damages the fort, with the Titan airstrike devastating parts of the outer wall, as well as ruining many buildings inside.
In the year 854, the weakened Allied Forces make their final stand at Fort Slava, a key tactical position protecting the Allied flagship fleet, stationed within the nearby naval-station. Marleyan forces wanted to take the area, knowing that attacking the port would be impossible without control of the Fort. The fortress held an armored train with anti-Titan artillery equipped, however, meaning that Marley would not risk deploying its Warrior forces. Therefore, battle was at a stalemate, with the 800 man unit of Eldian ground forces attempting to dig trenches to better surround the Fort. However, this plan was halted when the front unit of the 800 Eldian unit was hit by explosives.
Commander Magath prepares the Warrior unit to charge, to destroy the armored train's tracks, but Warrior candidate Gabi convinces him to let her try to destroy it by herself instead. By violating international law and pretending to be a non-combatant, Gabi manages to get close enough to the railroad tracks to throw a cluster of grenades, derailing the armored train. This allows for the deployment of Galliard's Jaw Titan, who shields candidates Gabi and Falco from machine gun fire before it begins attacking the Allied soldiers itself.
The Jaw Titan continues its assault on Allied defenses, aided by Pieck's Cart Titan and the 800 man Warrior unit. Meanwhile, a nearby Marleyan airship receives confirmation of the destruction of the armored train, allowing the airborne operation to begin.
After receiving a flare signal, the Marleyan assault force hastily withdraws from the fortress, and the airship starts parachuting Eldians from above. The Eldian force is then transformed into Titans while in mid-air using the power of Zeke's scream. This creates a kinetic bombardment airstrike, which devastates Fort Slava's wall and defenses. This strike kills roughly 60% of the Titans, with the rest being quickly killed by the anti-Titan artillery. Reiner parachutes from the airship before transforming into the Armored Titan and begins to destroy the 30 remaining anti-Titan artillery units in the fort. Galliard's Titan rejoins the fray, helping to save the Armored Titan from an armor-piercing shell, which then destroys the last few artillery units.
With the situation under control, Zeke joins the ground forces as the Beast Titan. It takes a fist full of armor-piercing shells, aims at the Allied navy fleet, and hurls the shells down towards them. The fleet manages to return fire at Zeke, before being destroyed, but Zeke is saved by the intervention of Reiner, at cost of the Armored Titan being destroyed by technology for the first time in history. This moment signifies the end of the Marley Mid-East War.
A meeting is held by Marleyan officials inside a ruined building in Fort Slava. Zeke is reprimanded by a Marley general due to the chaotic nature of the battle's conclusion, and Magath describes the declining authority of the power of the Titans, due to technological advancements made by other nations. He advises that Marley should stop its reliance on Titans, however, Zeke suggests that now represents the perfect time to resume the Paradis Island Operation. He expands, saying that Marley should focus on developing conventional weaponry,
whilst the rest of the world sits in fear of Marley's enlarged number of Titan powers. This advice is taken up by the general, who promises to bring it up in group discussions.
Later, Zeke and his successor, Colt, speak atop a building about his abilities as the Beast Titan. Zeke says that when he inherits his power, Colt may learn his secrets. Magath joins the conversation and they discuss the multiple dangers present on Paradis Island.
The Marleyan army withdraw from Fort Slava, to return to Liberio in Marley, having annexed the land from the Mid-East Allied Forces.
- The katakana spelling of Slava (スラバ Suraba?) could be an anagram of "Basura" (バスラ), which is the Japanese name of Basra, the second highest-populated Iraqi city.
- Slava is a word that appears in numerous Slavic languages, and translates as "glory" or "fame". This word is also the etymological source of the name of the Slavic ethnolinguistic group.
- The events that occurred at Fort Slava mirrors to the Battle for Hill 203 in the 1904-05 Russo–Japanese War where the Japanese infantry were forced to make mass assaults on an outmanned position defended by modern firearms including Maxim Guns.