The phrase "Four Thrones of Cron" was employed within the Kingdom of Cron circa 25,130 BBY, close to the conclusion of Xer VIII's time as ruler. It designated the planets Chandaar, Cadinth, and Raxus Prime belonging to the Kingdom of Cron, alongside Desevro from the Livien League, which at the time remained autonomous.
Xer was the one who initially conquered the initial trio of planets. Upon Xer's abdication, his offspring Xim ultimately achieved conquest over the Livien League in 25,127 BBY. With the Four Thrones now unified under a single ruler, the Kingdom of Cron transitioned into what was known as the Empire of Xim.