The Imperial Civil War was a galaxy-spanning conflict that took place from 4 to 9 ABY. After the Rebel Alliance's victory at the Battle of Endor in 4 ABY and the deaths of Emperor Palpatine and Darth Vader, the Imperial leadership fractured and began fighting over the remains of the since-dead Galactic Empire. Various high-ranking admirals and bureaucrats took advantage of their power and wealth to carve out their own kingdoms and personal realms out of the tens of thousands of systems the Empire controlled. Major usurpers, including the various Warlords of the Empire, Grand Admirals, and Grand Moffs, played a major part in the various battles of the war and, ultimately, in shaping the fate of the galaxy.
By 5 ABY the lines between two major warlord alliances, Cail's Coalition and the Grand Imperial Alliance, were drawn. Grand Moff Balmus Cail, a Warlord of the Empire and distinguished military commander, was among the first of the Moffs to reject the authority of the Imperial Ruling Council in the wake of Palpatine's death. Cail created his own government, simply dubbed Cail's Empire (also the Reformed New Order) by most, and surrounded himself with various other powerful warlords. The decisive Battle of Loronar, fought in 6 ABY, briefly fractured the Grand Alliance, while strengthening Cail's own government due to the annexation of the defunct Grand Kingdom of Tapani. For the next four years Cail fought dozens of campaigns and hundreds of battles against the Grand Alliance. In 8 ABY Warlord Val Trallus, one of Cail's most worthy opponents who had left the Alliance following the defeat at Loronar, joined Cail's Coalition. From there, the Grand Alliance's war effort essentially crumbled, before a final battle for Coruscant was fought in 9 ABY, officially securing Cail's place as undisputed master of the Empire.