Mandalorian Excision

The Mandalorian Excision (Te Dral'han, often transliterated as "the Annihilation") was a conflict in the Mandalore sector that saw the rise of the New Mandalorians (most of whom sought to eradicate traditionalist Mandalorians) and the destruction of many prominent Mandalorian clans. It was the Republic's first and only use of nuclear weaponry during the Great Peace era (1000-44 BBY)

Prelude
In the centuries immediately following the rise of Mandalore the Uniter during the late New Sith Wars, the Mandalorians experienced another period of unity as well as industrial and military might. Initially, the rulers of Mandalore sought to avoid direct contact - positive or negative - with the Galactic Republic, leading to a degree of neutrality at the time. However, after a Mandalorian invasion of Hutt Space in around 850 BBY, Republic politicians began to fear that the Mandalorians were going to invade Republic space, which the Mandalorians have done dozens of times over the millennia. A local political movement known as the New Mandalorians (Evaar'Mando'ade or Evaar'la Mando'ade) rose on Mandalore and Kalevala during this time. These New Mandalorians sought to reform the Mandalorian civilization into a more modernized society and to abandon Mandalorian traditions in favor of adopting Core World culture. Naturally, the Mandalorian traditionalists began to oppress these "pacifists", leading to more outrage in the Galactic Senate. This ire culminated into a Republic invasion of the Mandalore sector in 760 BBY, though the Republic invasion fleet was destroyed by Mandalorian warships. Republican politicians became divided on whether or not another attempt to occupy Mandalore should be made, which prevented another invasion attempt for nearly three decades. Many politicians eventually agreed that the New Mandalorians were a more suitable ally in that area of space, leading to another invasion attempt in 738 BBY with the goal of establishing the New Mandalorians as the dominant force in the area, which would secure the Republic's influence there. The second Republic fleet was once again swiftly destroyed by Mandalorian warships, though only one month later another Republic fleet was deployed, which was equipped with nuclear weapons. Republic admirals had much better luck defeating the Mandalorian warships during their third attempt, and only one week into their invasion of the sector they reached the Mandalore system, culminating in a massive space battle that lasted over two months. Most of the Mandalorian fleet consisted of ramships, which were considered millennia out of date by Republic standards. Though no Republic infantry were deployed on Mandalore's surface, many New Mandalorians volunteered their services to the Republic and formed militias that combated the warrior clans with technological support from their Republic allies. Many of these militias were defeated as the space battle ensued, prompting Republic admirals to use their nuclear weapons. Over sixty nuclear bombs were deployed, of which fifty-eight detonated (the other two failed to detonate and would not be recovered for a few centuries). At least ten nuclear bombs were also deployed on Mandalore's moon, Concordia. As the bombs detonated, what remained of the Republic fleet retreated from the sector. While many Republic citizens thought the decision to bombard Mandalore was necessary, outrage sparked among the liberal populations, who deemed the actions unnecessary and genocidal. A law was passed by the Galactic Senate which required the Supreme Chancellor to authorize the use of nuclear weapons, as admirals were previously allowed to deploy their bombs in battle without approval. This law eventually evolved and led to the use of nuclear weapons being completely banned within the Republic Navy.

Aftermath
Of the estimated 2,500,000 individuals that inhabited Mandalore and Concordia at the time, more than 1,700,000 (civilians and warriors alike) were killed as a direct result of the explosions or having later died of radiation poisoning, leaving a population of only around 800,000. Long-term affects of the radiation also led to many later generations being born with deformities and a higher mental illness rate. Nearly 35% of Mandalore's surface was decimated into a desert landscape, which later came to be known as the Death Desert. Much of this desert was barely habitable due to either high heat or the local predatory species that settled there. Another 10% of the surface was deemed completely uninhabitable to both plant and animal life, leaving behind fruitless dirt mounds for kilometers on end. Many significant clans were either completely destroyed or forced to relocate to other Mandalorian worlds such as Concord Dawn, Ordo, and Vorpa'ya. Those that remained on Mandalore fell into infighting, allowing New Mandalorian clans to dominate the Mandalore system, eventually establishing the Duchy of Mandalore as a member of the Galactic Senate.

Traditionalist clans would reemerge at several points in the following centuries and formed confederations that began to reconquer many territories lost to the New Mandalorians. By 100 BBY, a majority of the New Mandalorians' territories were pushed back to only a few cities in the Death Desert and on Kalevala. Despite this, the Duchy maintained Republic support and its economic influence across the northern Outer Rim. In 20 BBY, the Duchy collapsed after Duchess Satine Kryze was murdered and many of their remaining cities either seceded or were besieged by traditionalist clans.