The Republic-Mandalorian War was a major galactic conflict which erupted in 4,026 BBY and had devastating effects that would take almost 3 millenniums to fix. What begun as a small rebellion resulted in the reorganization of the entire Galactic Jedi Republic into mere holdout remnants which would eventually be absorbed in to the Galactic Union.
Golden age of the Jedi
Before the outbreak of the war, the Jedi enjoyed their golden age since the fall of the Trico-Frost Sith Empire which collapsed after an on going cold war between itself and the Republic as a result of the Great Rebellion. What had remained of the empire was mere remnants, which were now the threat which arose to destroy the Republic. The Jedi then enjoyed several decades of reconstruction and expansion, until the birth of one named: Omuk de-Frost, who was raised as a Jedi, but after a destiny changing mission, apprenticed himself to his ancestor and restarted his life as a Sith Lord.
Beginning of disorder
Four years before the beginning of the war in 4,030 BBY, the Mandalorians begun organizing an independent government with an independent army, which begun to threat the peace of the republic. After a year, these series of events led to the outbreak of a crisis, known as the Mandalorian Crisis (Republican Era). A series of skirmishes erupted between Republic forces and Crusader forces which lasted for three years. At the end of the crisis, the Mandalorian Empire was under the control of a Dark Lord, who led the Mandalorians to declare war against the republic.
Beginning of a war
After taking control over the Mandalorian Empire, Darth Admer caused a chain of events which led to the declaration of war against the Republic. The Mandalorian Army, which was under the command of Mandalore the Deceived, attacked countless Republican outposts mainly in the Outer Rim Territories which already struck a severe blow to Republic holdouts there. The Empire led countless troops to war against the Republic, and to every system they arrived, they struck fear and control over it. The Republic, already harmed by the Mandalorian Crisis (Republican Era), attempted to attack Mandalorian holdouts themselves, but with limited success. The Republic was already on its way to collapse.
The first of the Crusaders' targets was the peaceful and quiet living planet of Ithor, where the famous Ithorians, have built their society in peace and undisturbed. The planet was an excellent target since it was a major Republic holdout in the Outer Rim and a well-known Republic ally. Under the command of Darth Admer, the crusaders were successful capturing the world and destroying all republican presence in the system. this battle blew a severe struck to the republic, and opened opportunities for more invasions to Outer Rim systems. The battle took place in 4,026 BBY.
After the Battle of Ithor, Darth Admer decided that Onderon has a potential of becoming a major staging area for the Sith empire, and called for an invasion of the world. After a harsh and victorious space battle, the planet fell under the crusaders' blockade. Under the Dark Lord's influence, the local population rebelled against the Jedi, and the planet fell into Mandalorian hands. After its fall, Admer visited Freedon Nadd's tomb and achieved an even greater knowledge of Sith Sorcery, which allowed him to increase the Mandalorians' war efforts against other Republic forces. The battle took place in 4,026 BBY.
After taking control and basing the Mandalorian rule on Onderon, he continued his invasion of the galaxy and decided to remove Republic presence in all core Sith territory, primarily Korriban and Ziost. He took a Mandalorian fleet, and occupied the former Republic space station which orbited the world, leaving no survivors. The Jedi who served aboard the space station fought ferociously against him and his armies, but failed in preventing them from conquering the planet. The space station remained intact.
After securing both orbital and ground bases, he then discovered ruins of a Sith academy on Korriban. After exploring its inside, he found a holocron which changed the face of the war. The battle took place in 4,026 BBY.
Several months after the battle of Korriban, many battles were fought, minor battles primarily. One effective battle was the battle of Ord Mantell, which took place in 4,025 BBY and was fought between the Galactic Jedi Republic and the 3rd Mandalorian Crusaders. The battle was short and decisive, but had a major role in the war, since the planet was full of scrapped metal which were later reused to create hundreds of thousands of warships for the 3rd Mandalorian Crusaders, using the Union's Treasure.
After retaking Korriban from Jedi hands, and commanding many other battles against it, Darth Admer discovered a Sith Holocron which led him to the uncharted Lehon system, where the former galactic Rakatan Dynasty began to form almost thirty thousand years ago. After arriving there, he was greeted by the local Rakatans, who accepted him with great respect and organized a festivity especially for him. After several days, he somehow reunited all the Rakatan nations to one, and technically restored the old Rakatan Dynasty and reorganized it into a part of his new empire. The Rakatan population, which numbered almost 632 billion, joined the war effort on Admer's side. All the Rakatan warriors who served in the empire numbered almost 4 billion troops. After this, his armies were no longer outnumbered by the Republic.
The Rakatans then led him to their most secret ancient memorial, known by then, as the Rakatan Citadel; a super-massive space citadel, which had other facilities, such as a weapon and ship factory, a hyperspace missile launcher and a personal throne room. In the end of the war, the citadel was renamed by Admer himself to the Union's Treasure, and it continued to manufacture military goods until its destruction. The mission took place in 4,025 BBY.
Three years after the beginning of the war, the Mandalorians had crippled the Republic and brought it to the edge of a political collapse, when many senators saw the security the Republic offered its worlds and citizens. It was then that the Jedi Council decided to make a bold move and attack the Mandalorians' capital of Mandalore. Gathering what ships and men it could, the Republic then began moving millions of troopers in its unharmed staging areas, and centering them in systems near by Mandalore.
The unsuspecting Mandalorians then realized they were facing a full-scale invasion to their beloved homeworld, but it was too late. The battle began, and the Mandalorian forces were almost completely wiped out, while the Republic forces suffered almost no casualties.
However, thanks to Admer's newly obtained Sith Sorcery Spell Book, he summoned a worm hole, which swallowed many front line Mandalorian ships and returned them to Mandalore, where the remaining forces were stretched thin. The battle was eventually won, but the Mandalorian casualties were far larger than the Republic's. This battle was a devastating blow to the Mandalorian fleet and allowed the Republic to retake several lost systems until the Mandalorians were back on their feet. The battle took place in 4,023 BBY.
After the Pyrrhic victory in the Battle of Mandalore, the Mandalorian presence in their newly acquired systems was thinner than before, allowing the Republic to retake several systems before the Mandalorians were back on their feet again. Ord Mantell was a crucial world which held trillions of tons of reusable metal which until then was reused by the crusaders. The Republic retook the world in a swift and easily won battle against the Mandalorian forces there.
After the battle of Mandalore, the Mandalorian fleet was stretched thin in newly conquered worlds, which allowed the Republic to retake a limited amount of these worlds. Encountering an unidentified life form, the Rakatans, the Jedi interrogated these aliens and shortly discovered their homeworld of Lehon. After realizing the truth about the enormous Mandalorian military factory, they assembled a task force of almost 1,000 ships to aid in this battle. After planning the battle and acquiring very inaccurate schematics of the space station, they sent the fleet to engage the Mandalorian fleet in orbit of the planet.
The battle was one of the longest battles fought in the war, taking more than 6 months of an ongoing battle. Eventually, the Republic fleet succeeded in destroying the Mandalorian war machine, but the price was heavy. Out of 1,000 capital ships, 20,000 fighters, and 4,000 smaller ships and corvettes; only 54 capital ships, 1,452 fighters and 203 corvettes remained in the Republic fleet.
The Mandalorian fleet however, was completely wiped out as the Rakatan Citadel fired an accidental hyperspace missile as the battle raged on in the sixth month. After the Mandalorian fleet was destroyed, the Citadel then blasted out from hyperspace to deep space. The Jedi were certain that the station was destroyed in the battle, but they would not know about it until the Great Sith Acquisitions. The battle took place in between 4,023 BBY to 4,022 BBY.
The beginning of the Core Worlds Campaign depended on the success of this battle, since it would soon become the Crusaders' first foothold in the Core. After the beginning of the battle, the republic space forces were almost completely wiped out by the imperial forces, in a very easy battle. The most decisive factor was Admer's force meditation he used from his capital ship, The Union's Fist, in his private meditation chambers. The space battle was won, but the ground assault was still undecided. After calling over a million Rakatan and Mandalorian troopers to invade the world, the local resistance continued to rise up against the Mandalorian tyranny.
The uprising continued to rage across the world in post republic outpost built all over the planet. Eventually, the force was successfully corrupted by Admer's dark side power, and the population changed sides to become loyal to the Crusaders. The world was an important foothold in near core worlds territory, and three months after the occupation, the Core Worlds Campaign was issued, which delivered a most devastating blow to the republic galactic support.
The battle of Corellia, took place in 4,022 BBY in the Core Worlds Campaign during the Republic-Mandalorian Wars. After gaining foothold in Corulag, the Mandalorian armies were preparing for a long-thought campaign which was issued by both Darth Admer and Mandalore the Deceived which were supposed to lead the Mandalorian Empire to a decisive victory against the Jedi. The battle was the beginning of a series of hit and run assaults, which destroyed all the Galactic Jedi Republic resource production factories and mines, which would lead to them taking control over civilian resource production, thus causing anti-republic operations and uprisings to begin planet wide. Eventually, the population decided to join the Mandalorian Empire and banish every republic presence from their systems.
The battle of Abregado-Rae, was a battle which was fought during 4,022 BBY, between 3rd Mandalorian Crusaders and the Galactic Jedi Republic. The battle was planned by Darth Admer and was supposed to take control of this world, it being famous to be a smuggler's hangout place. After taking the world from the republic, their smuggler support was drastically decreased, causing more and more worlds to abandon the Republic cause and join the Mandalorian Empire.