Yes, ancient China did conquer another civilization. The Xiongnu were a nomadic people who lived in the steppes of Central Asia. They were a powerful and warlike people who had long been a thorn in the side of the Chinese. In the 2nd century BC, the Chinese emperor Wu of Han decided to take action against the Xiongnu. He sent a massive army into the steppes, and after a long and bloody war, the Xiongnu were defeated. The Chinese then annexed the Xiongnu territory and incorporated it into their empire.