First Telom War

The First Telom War was an interstellar war between the Ur-Han and the Telom Nation and the Surben Republic. It is considered to be one of the earliest interstellar conflicts in the known galaxy on a large scale. This conflict would set the basis of military strategies and tactics for the following centuries. 
The war began in 2016, when the Ur-Han invaded the Telom Nation. The Telom Nation had been in good terms with the Surben Republic, but due to internal unrest, and the lack of a proper navy it initially refused to join. The Telom capital was besieged by 2020, and the Surben Republic entered the conflict. The Mirdesh Federation provided aid to the Telom and the Surben, but did not directly join. The Ur-Han were pushed out of Telom space by 2023, but it was impossible to make a push into Ur-Han space. By 2026, the war had effectively come to a halt, with minor skirmishes being the only last form of conflict. A peace treaty was signed in 2028. Neither side gained or lost any territory.
The treaty did not impact nations directly. However, it had a lasting societal impact. The Surben, Mirdesh and Telom had so far peacefully expanded without having forms of conflict comparable to wars. The Ur-Han, which had already subjugated the Tesrat, were not prepared to face an opponent which they were unable to defeat decisively. As a result, in the following decades, all nations in the galaxy drastically increased their military spending and research. The period following the war, up until the early 22nd century is known as the 80 Years of Darkness, when nations retreated into isolationism, economic and demographic growth abruptly stopped, and militarism increased throughout the galaxy. Multiple small-scaled conflicts would follow the war and ultimately lead to the Second Telom War.