What was the fate of Attila the Hun after his defeat at the Catalaunian Plains?

After the battle at the Catalaunian Plains in 451 AD, Attila the Hun did indeed retreat. This battle marked a significant confrontation between the Huns and a coalition of Roman and Visigothic forces. Though Attila had been a formidable opponent and had posed a serious threat to the Roman Empire, the defeat he suffered at this battle led him to withdraw his forces.

His retreat did not immediately diminish his power or influence, as he continued to rule as a leading figure of the Huns for a period after the battle. However, this event was crucial in stalling his campaigns in Western Europe and contributing to his eventual decline.

The other choices do not accurately reflect the historical context following the battle. He did not become a king of another territory, nor did he die in that battle, and while he faced some setbacks after this defeat, he remained a significant figure until his death.