Galactic Empire

The Galactic Empire was the term awarded to the Imperial government that followed the First Clone Wars. It had multiple incarnations, and multiple reforms that resulted in various guises, be them under the title of the 'Galactic Empire' or simply the 'Empire'.

Birth
The Galactic Empire was the culmination of a millennium of planning by the Sith Order, resulting in Darth Sidious claiming the throne by reforming the Republic in response to the 'depradations' of the Jedi Order and the Confederacy of Independent Systems. With the calling of Order 66, the Chancellor could complete this reformation, though the Imperial Senate remained intact.

The First Galactic Empire
19 ABY to 7 ABY

The First Galactic Empire proceeded to spend the following twenty years after the Clone Wars re-establishing the territory of the Old Republic over the galaxy, and beyond its old borders. Conquering Hutt Space and Mandalore it crossed old thresholds, and by 1 ABY had secured the entirety of the Separatist worlds which had escaped the Empire's attention, despite a Second Clone Wars breaking out in 11 BBY.

However, by this time the resistance to the Empire had become such that it could oppose it militarily. Started in 2 ABY, the Galactic Civil War Earth June 10th 2207 pitted the Empire against a Rebel Alliance, destroying the Death Star and inflicting numerous defeats upon the Empire, systems such as Fondor and Ralltiir becoming contested, and the Alliance amassing strength at the very ends of the Rimma Trade Route and Perlemian at Nocto and Mon Calamari.

The Galactic Empire wounded the Alliance badly at the Battle of Hoth in 3 ABY, but a year the Battle of Endor killed the Emperor and much of the Imperial heirachy. With no head, the Empire began to split into competing factions. A short lived resurgence collapsed, and the Alliance pressed upon Coruscant and finally captured it in 7 ABY.

The First Empire
7 ABY

The First Empire was established on defeat, and rapidly began losing ground. As the stewardess of the Empire carved out her own warlord fiefdom at Thyferra, battles at Chandrila and the surrender of key worlds such as Alsakan and Metellos kicked the Empire clear from the Core, holding onto Kuat and Corellia.

Imperial territories in the Colonies and Outer Rim began to join warlord Zsinj, and by the time the Bacta War ended the Empire held onto very little territory. Of the million member worlds that made up the Empire, 600,000 joined the New Republic and the around a third of the old total sided with Zsinj. Within the remaining 170,000, the Deep Core held more than 120,000 member worlds, leaving the remaining 50,000 to be scattered amongst the other warlords and the Imperial Remnant.

The Second Empire
8 ABY to 9.5 ABY

The Second Empire came about from the defeat of Zsinj, the Ruling Council moving warships to secure whole swathes of territory, bringing the overall Imperial control back upto 25% of the galaxy, but for the loss of Kuat and it's massive shipyards. The two sides were equal in strength, the New Republic having the advantage of resources. Grand Admiral Thrawn turned this around, launching a masterful assault which doubled the size of the Empire.

However, his untimely death, and the destruction of recently discovered cloning centers on Wayland cut short the offensive, and the Alliance fleet advanced from the Core on the Outer Rim, the Imperial Fleet vanishing from view. With the death of Thrawn, the Empire lost its new territory in less than a fortnight.

The Second Galactic Empire
10 ABY to 11 ABY

The Deep Core finally rejoined the Imperial war effort, revealing years worth of construction. World Devastators were unleashed, and the Empire reclaimed Coruscant once more. With this new lease of life came the resurrected Emperor, who recaptured more than half of the galaxy, shattering the New Republic. This offensive cost the Empire massively, but it did the same to the New Republic, reducing them to a few thousand member worlds. The Galaxy Gun enabled the Emperor to retain control, but the untimely loss of that, the Emperor himself and the planet Byss and all its shipyards completely unravelled the Empire, and it collapsed in a matter of days.

The Third Empire
11 ABY to 18 ABY

The Third Empire was made almost immediately after the death of the Emperor, as the split Imperial military retreated from Coruscant and other key Core worlds, and the Deep Core largely seceded from the mainstream Empire. The new government was focused around the Imperial Ruling Council. An interregnum of continuity occured, as the warlords became equal partners of strength within the new regime, though none would admit as much. To add additional issues to the new Empire, elements within the Outer Rim founded their own factions, and the Mid Rim was largely abandoned by High Admiral Teradoc, costing the Empire a chunk of territory from the Deep Core down the Hydian to the Corporate Sector.

The Council made efforts to consolidate control of the militaries of the warlords, Admiral Daala eventually uniting thirteen of the warlords under the Ruling Council. But by this point the Ruling Council was caught in a tide of political in-fighting, eventually resulting in power moving from the old court to the Moff Council. The Empire eventually withdrew to secure the Outer Rim provinces of the Empire, losing its territory between the rim and the Deep Core, which itself re-unified into the Imperial Core.

The two factions - the Third Empire and the Imperial Core - made efforts to engage the New Republic, but eventually the Empire was destroyed at the Battle of Anx Minor, which dove the Empire from over a hundred sectors to eight small sectors on the edge of the Unknown Regions - the Imperial Remnant was born.

The Fourth Empire
From the ascension of Emperor Fel I to 130 ABY

The Third Galactic Empire
130 ABY

The Fifth Empire
130 ABY onwards