The Buyuk Empire agreed to withdraw all starships from the Greenwater Nebula, and in exchange, the Karalian Empire and the Confederacy of Greenwater were banned from entering the Galactic Core Zone. The reason for this truce was for the Buyuk to be able to concentrate their forces on the Eteno Imperial Triumvirate, but the Buyuk had neglected to inform the Karalians of this information to prevent (or rather delay) the possibility of the KE teaming up with the EIT.
The armistice managed to last nearly 300 years before it was breached during the Ankodega Incident. Since then, border conflicts ensued in regards to where the exact armistice line was until the war reignited once more. Despite this, the truce was "officially" still in effect.
Armistice of 1439 4AKE