The Battle of the Illinois Sector occurred in 2324 when the Klingon Empire attempted to reclaim its former colony of Chal. By this time and with the assistance of the United Federation of Planets, the Chal had become a thriving society with a strong Star Fleet of its own. The battle occurred on the extreme section of Sector 021, also known as the Illinois Sector, within Federation space. To their credit, the Federation held back from intervening, although much later a top secret memo reveled that a Federation taskforce was waiting to assist the Chal if needed, which was never requested. This event would lead to the founding by the Chal people of the Cha'ouw Empire.