The original purpose of the Great Wall of China was to protect Chinese states and empires from invasions and raids by nomadic groups from the north, particularly the Mongols. Constructed over several dynasties, starting from the 7th century BC, the wall served as a line of defense in addition to controlling trade routes and immigration. Beyond military use, it also functioned as a symbolic barrier, representing the power and determination of the states that built it. Over time, the wall evolved into a national symbol and an enduring testament to ancient Chinese engineering and fortification techniques.