"五胡乱华" refers to a period in Chinese history during the late Han Dynasty when five nomadic tribes, known as the Five Barbarians, invaded and settled in northern China. This era, which lasted from the late 2nd century to the early 5th century, led to significant social and political upheaval, as these tribes disrupted the existing Han culture and governance. The term literally translates to "Five Barbarians Disturbing China," highlighting the chaos caused by these invasions. The Xiongnu, Qiang, Xianbei, Di, and Mongols were the main groups involved. This period ultimately contributed to the fall of the Han Dynasty and the rise of the Three Kingdoms era.