Imperial power struggle

The post-Endor Imperial power struggle was an internal conflict in the Galactic Empire that lasted from 4 ABY to 9 ABY. As various Imperial warlords vied for power and resources, creating their own fiefdoms, the New Republic went on the offensive and managed to take and much of the Core Worlds. Although the Imperial factions were eventually reunited under a former Dark Side Adept named Vastir Tokrev, who proclaimed himself Galactic Emperor, the Imperial Armed Forces and the economy were devastated by the internal conflict. The power struggle effectively ended the Empire's domination of the galaxy, which it would not regain before embarking on the Core Offensive in 9 ABY.

Prelude
Due to the fact that Emperor planned on ruling the Galactic Empire forever using clone bodies, he did not designate an heir apparent to take his place in the event of his demise. He also encouraged distrust and competition among his subordinates, including Imperial Advisors, Moffs, and military officers, keeping the upper echelons of the Empire divided. When he and, who held the rank of Supreme Commander of Imperial Forces, both perished aboard the during the  in 4 ABY, there was no clear line of succession. Soon after the news of the Emperor's death spread throughout, many Fleet commanders, Moffs, governors, and other officials went rogue and became warlords.

They began to carve out their own fiefdoms out of the carcass of the Empire, with many proclaiming themselves as the new Emperor. Grand Vizier Sate Pestage, the legal head of government, took control of the regime on as the interim Emperor, but lacked the charisma and political skill necessary to hold the fragmenting Empire together. The Imperial Ruling Council, the highest administrative body in the Empire, nonetheless attempted to restore order. However, many Grand Moffs and military leaders did not trust the Grand Vizier and refused to recognize his claim to the Imperial throne. Many of them ended up splitting off and joining the warlord fiefdoms, further straining the Imperial military. Some of the more prominent warlords included High Admiral Freyja Merlon and Grand Moff Pellar Hadrian, who took control of large swaths of territory.

However, Pestage's biggest threat was located on Imperial Center itself. , the ambitious director of Imperial Intelligence, attempted to take the throne for herself by carrying out a coup against Pestage and the Ruling Council with the support of several military officers. Pestage was tipped off, however, by an Imperial Intelligence officer named Valek Aracham, and was able to prepare. As Isard began her coup, COMPNOR responded swiftly, deploying the Imperial Security Bureau and CompForce to round up and arrest the conspirators. Isard herself attempted to resist and was killed in the ensuing firefight. Imperial Intelligence lost some of its best agents during the coup and lost prestige and trust in the eyes of the government. Pestage appointed Aracham as the new director of Intelligence, who set about reforming the organization.

Taking advantage of the chaos, the New Republic (the government established by the former ) began a push towards the Core, fighting Imperial loyalists and warlords alike. They reached Imperial Center a week after the coup attempt. The capital was heavily defended, but the New Republic brought the majority of its Starfleet for the assault. Although Imperial forces savagely defended their capital and gave the New Republic heavy casualties, Coruscant fell after a lengthy battle. Pestage and the Ruling Council relocated to, which became the provisional Imperial capital. Due to fears about his ability to lead, Pestage was removed from office by the Ruling Council shortly after their arrival.

Erosion of Imperial power
On Corsin, the Imperial Ruling Council was reorganized, consisting of Imperial Advisors, Moffs, governors, COMPNOR officials, and other Imperial nobles. Pestage was stripped of his rank but continued to be active in the Council. In an attempt to retake Coruscant, the Ruling Council let General Reynar Thalen, who remained a loyalist (at least outwardly) and commanded a large force, plan an an attempt to retake Coruscant. This move was opposed by other senior officers, especially by Imperial Navy officers, who did not trust an Army officer to plan out a campaign which would largely rely on naval power. Among them were High Admiral Markus Thrain-Zardel and Fleet Admiral Taro Korvin, two brilliant tacticians and strategists, who advised against it. The Ruling Council ignored their objections and ordered the military to go through with Thalen's plan. They also agreed to appoint Thalen the new Emperor, to solidify his support.

The Grand Fleet, a combined force of warships, moved in to attack Coruscant. However, the New Republic Admiral Vacander Malkhan anticipated such an attack, and thus several fleets were stationed at the capital to defend it. The Grand Fleet fought ferociously, but was ultimately defeated, with Thalen perishing aboard his flagship, but not before ramming the flagship of Admiral of the Fleet, the New Republic's Supreme Commander. The death of Ackbar was not enough of a consolation for the loss of a large fleet of warships, however, and the Second Battle of Coruscant was deemed an utter disaster by the Ruling Council.

Using his connections, Grand Moff Haldor Vicari was able to get himself appointed to the Ruling Council, being backed by major industrial leaders such as Tavrid Unteel, Garador Seiradan, and others. He carried out several somewhat successful operations against Imperial warlords, uniting more forces under his banner. However, in early 5 ABY, Grand Moff Vicari was found dead in his estate. His murder was never resolved by Imperial Security Bureau, which was quietly commanded to drop the investigation following the rise of Vicari's successor. A Dark Side Adept named Drogan Hestor used the Force to influence the Council into appointing him Emperor, and began to plan out a new offensive against the New Republic.

Before Hestor could, however, he was challenged and slain in late 5 ABY by another Dark Side Adept named Valus Darklancer. He then took power as the new Emperor, but a major New Republic offensive began against the Empire shortly after his ascension to the crown. Darklancer was a poor tactician, with Imperial forces being defeated and forced to give up many sectors. Humiliated, he led the remnants of his personal flotilla on a final, suicidal assault on the New Republic's First Fleet during the Battle of Palanhi, and perished.

Stabilizing the front
The New Republic offensive was stopped by Imperial forces not long after the battle and the front stabilized. With the death of Emperor Darklancer, the Interim Ruling Council appointed Moff Ergoth Deucalion to the position. The man was the former head of the Imperial Diplomatic Corps. An astute politician and skillful diplomat, he managed to negotiate with many warlords and bring them back under the Empire's banner, bolstering the weakened Imperial armed forces. He utilized Imperial Intelligence, working with Director Aracham, to spread rumors in the New Republic that agents helped the Empire bring down the planetary shields of  several years before the Galactic Civil War. The destruction of Camaas was one of the Empire's best-known atrocities, and the rumors resulted in a political scandal in the New Republic.

As a result, a ceasefire between Imperial and New Republic forces was agreed upon, while the new regime dealt with the internal crisis relating to the Bothans. Emperor Deucalion took the opportunity to launch operations against the last remaining major warlord, Grand Moff Hadrian. The Grand Moff's faction was routed by the revitalized Imperial troops in 7 ABY, with only a few minor warlords still remaining. However, in 8 ABY, the New Republic launched another operation against the Empire's holdings. The Imperial Fleet, to the Republic's surprise, was able to hold off the assault, but Deucalion was killed in battle. His successor became Grand General Bastell Carba, who ruled as interim Emperor for several months before a new leader emerged.

A new leader
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Notable battles

 * Battle of Ciutric (4 ABY)
 * Battle of Vinsoth (5 ABY)
 * Battle of Axxila (5 ABY)