The Great Crusade

The Great Crusade was a conflict that erupted a few months after the end of the Infinite War, which later escalated into a greater crusade against the Alliance and Splinter Factions organised inside of the Alliance.

Prelude
A few months after the end of the Infinite War, Jedi Knight Natalia H'edan was promoted to Master, and given a seat on the council. Natalia H'edan soon was elected Grandmaster, proving popular among the council, and she would soon sanction a group of Jedi to be sent to Mandalore as diplomats, where upon their arrival they were attacked by the Order of Neo-Crusaders, and taken hostage. The Jedi would demand their release, threatening war, and gave them a deadline of 2 months. Meanwhile, the Alliance, already fractured as a result of the Infinite War, did not wish for a war, but the Jedi were basically one of the only things holding the Alliance together.

The Opening Days
2 Months after the deadline was issued, the Jedi would mount a large assault on Mandalore, being hugely successful and capturing much of the planet. The Mandalorians would then proceed to recapture most of the planet, killing many Jedi and Alliance soldiers, and forcing them to retreat. A month after the initial invasion of Mandalore, while the planet was still mostly embroiled in warfare, multiple Admirals, Generals and Senators thought that another war directly after the Infinite War would destroy the Alliance, and would succeed, believing the Alliance would be too weak to focus on two fronts. Days later, the Alliance declared war, and sent its Armada to defend Coruscant, where the Splinter Factions had launched an attack with a combined fleet. Elsewhere, the Splinter Factions began to lose ground, and the Mandalorians pushed the Jedi off Mandalore by 243 ABY.

2nd Siege of Coruscant
The Mandalorians, after pushing the Jedi off Mandalore, would launch a gigantic offensive into Alliance space, where they met little resistance due to the Splinter Faction front. A single Mandalorian fleet would arrive at Coruscant in an attempt to quickly and swiftly end the war, where they would be engaged by almost all of the Jedi and a combined force of Alliance Soldiers, Coruscant Police, Alliance Sympathizing Militias and Senate Guard. The Mandalorians ultimately were dealt a heavy blow and pushed back almost the entire way to Mandalore.

Middle Years
The war persisted in stalemate for years, with the Mandalorians unable to beat back the combined might of the Jedi and the Alliance, and the latter being able to beat back the very skilled Crusaders. By 244 ABY, the Splinter Factions had almost lost all of their holdings to the Alliance, and all their fleets for a final stand.

Battle of Empress Teta
The armada assembled by the Splinter Factions launched an assault on Empress Teta, capturing the undefended planet within days, but gaining the attention of the Republic, who sent a gigantic fleet to the planet. Eventually, after taking out many ships, the assembled armada was overwhelmed and defeated, ending the battle and the Splinter Factions, but also drawing a large amount of Alliance forces away from the front.

End Days
The Armada dispatched to Empress Teta was part of a large fleet along the border of Mandalorian-Alliance Space, meant to defend against Mandalorian assaults, and left a hole in the fleet sizeable enough to allow a fleet to slip through. A group of Mandalorian admirals would combine their fleets into a large armada, and launch an assault on the Alliance Fleet, using their much smaller, faster ships to quickly get through the gap, and enter Alliance Space. Due to the flank, the Alliance began sending multiple fleets to combat them, allowing the same tactic to be used all over the front, and ultimately culminate in the 3rd Siege of Coruscant, where the Mandalorians would ultimately be repelled, and put on the retreat for a short while. Eventualy, a peace would be brokered at the Treaty of Alsakan.

Aftermath
Even though the Mandalorians ultimately defeated the Alliance, they suffered large casualties, and did have as much Population or Industry as the Alliance, and would lose many gained systems to successful rebellions. The Grandmaster of the Jedi Order at the time, Natalia H'edan, was hailed as a Alliance Hero, even though the war was ultimately lost.