The Great Wall, as we know it, is actually a series of several walls built at different times by different emperors.
Second Great Wall - built by the Han Dynasty 205-127 BC
Third Great Wall - built by the Jin Dynasty 1200 AD
Fourth Great Wall - built by the Ming Dynasty 1367-1644
The First Great Wall was ordered built in 214 BC by Qin Shi Huangdi after he had finished consolidating his rule and creating a unified China for the first time. The wall was designed to stop raids by the Xiongnu raiders from the north. 500,000 laborers were used during the 32 year building period to create the First Great Wall. Detailed