The most important landmass on Nishr was the continent of Feldt. The terrain was predominantly open and low-lying, but climate and landscape varied: there were temperate areas and desert, forests and rough ground, and at least one area of significant upland, accessible only through passes. There must also have been seas surrounding Feldt.
During the era of the Galactic Empire, the native Nish were still primarily in a feudal stage of development, but in the southern regions of Feldt, below the mountains, an industrial society was developing, and several cities had grown up on this continent.
In Fourth Month of 2 BBY, a small Imperial garrison was deployed to Nishr, and accompanied by Imperial Mining Corporation surveyors. Major General Vin Kollis of the Imperial Army was appointed as garrison commander and Planetary Governor
Governor-General Kollis was not a hard-liner, but abuses by his troops provoked the natives into rebellion, leading to the bloody Nishr Suppression. Around Sixth Month of 0 ABY, reinforcements were dispatched to secure control, raising the garrison to regiment strength, and these events caught the attention of the Rebel Alliance, which dispatched a fast-moving armored force designated the Nishr Taskforce, under Major Fisk Csino. Their mission was described formally as giving support to the local insurrection, but its real agenda was to tie down unnecessary numbers of Imperial troops on Nish, drawing them away from locations elsewhere in the Sector.
Thus began the Nishr Campaign.
The Alliance task force was much smaller than the Imperial garrison, essentially just a reinforced company of light tanks and scout cars, and it was only able to secure limited local support. The majority of the Nish remained subdued after the Suppression. But the Alliance enjoyed one major advantage. The Imperial TIE/LN starfighter wing assigned to the planet had been wiped out by Rebel starfighters covering the deployment of the taskforce, depriving the garrison of air cover to combat the agile Rebel repulsorcraft.
Eventually, the Imperial garrison's main mobile force was lured into a trap, and largely eliminated. This left Kollis with just infantry and lumbering walker armor, neither of which was able to maintain territorial control. The Imperials retreated back into the uplands, securing the passes with troops, and falling back on the heavy weapons of their base.
Stalemate ensued: the Rebels could not challenge the Imperial base immediately, and the Imperials could not secure the reinforcements that they needed to retake lost ground.
It is not known at present what the outcome of the campaign was.