In 50 ABY, the Galactic Alliance reformed itself into the New Republic behind the renowned and formidable Senator Karia Straden from the world Corellia of the Outer Rim. Up until that point, Corellia was an independent world, but with Senator Straden's election as the last Chief of State of the Galactic Alliance and eventual election as Supreme Chancellor of the New Republic, the separatist Corellians were all but enamoured with the Republic and their benefitting interests which they hoped it'd represent. Chancellor Straden began her term as head of the major galactic government in 49 ABY and it was her who set the galaxy on a course of renewal. Working closely with the Moff Council of the Imperial Remnant, she paved the stepping stones for peace. The Coruscant Concordat was meant to put an end to the escalating tension between the two galactic governments. Indeed, under the leadership of Grand Moff Pollix Yomaros, the Imperial Remnant was able to work closely with the New Republic and build on peace.
Unbeknownst to the galaxy at-large, the long held notion of the demised Sith Order proved to be untrue. Looming over the galaxy like a beast awaiting its prey, the Order orchestrated a series of intertwined events that would set the two dominant galactic powers down an unexpected journey. Chancellor Straden would resign after 12 years and Moff Yomaros would fall ill in 62 ABY. In their separate paths to retirement, they both would work equally diligent in allocating a successor. From Straden came a capable Mon Calamari diplomat by the name of La-Kai Dontin, and, from Yomaros, came Adiara Reth. The new Supreme Chancellor and Grand Moff laboured to maintain the peace of their successors, uniting forces when the Sith threat became a reality. Recognizing that though the Sith's fleets could be destroyed they could never be conquered as an Order, the two galactic powers became resolute in their campaign - using the combined efforts of the Jedi and Imperial Knights - to obliterate the Sith culture.
For a time, the joint assault forces kept the Sith on the run. Consequently, the Republic and the Imperial Remannt became strong allies. It was that this shared perception of brotherhood made the rise of the Imperial-Republic War all the stranger. Gradually, the Imperial Remnant restructured into the Imperial Order, reforming itself along somewhat more democratic lines and welcoming aliens among its military ranks. The Grand Moff worked hard to rid the military and government of hardliners--those termed "New Orderists"--while the Supreme Chancellor assisted however possible.
By the end of 79 ABY, the Sith were vastly diminished in numbers, and galactic civilization seemed to be re-adjusting to the idea of stability. One more battle meant one less day of war...or so the propaganda told them. The Sith's machinations culminated in the souring of relations in early 79 ABY and the outbreak of war by 82 ABY. The deaths of the Surpeme Chancellor and Grand Moff shocked the public, and widespread support was given for military rebuilding and upgrading. The New Republic maintained a vast majority of the resources; the conflict that would become the Imperial-Republic War was more of the New Republic slowly creeping into Imperial Space.
By 94 ABY, the war was coming to a slow end. The New Republic began to show cracks and war weariness; internal power struggles elevated between the Jedi and Republic leadership and public desire for a quick resolution to the decade-long war had been called for time and time again. Supreme Chancellor Elak Aadedai, a human from Anaxes, maintained a staunch pro-war position, demanding absolution from the Republic and launching all their numbers at key enemy worlds and supply lines with the expectation of victory. This was the same Chancellor who would end up with a lightsaber through his chest that would ultimately spark a bitter conflict in a galaxy...far, far away.