The Terracotta Army was buried with the Emperor of Qin (Qin Shi Huangdi) in 210-209 BC (his reign over Qin was from 247 BC to 221 BC and over unified China from 221 BC to his death). Their purpose was to help rule another empire with Shi Huangdi in the afterlife. Consequently, they are also sometimes referred to as "Qin's Armies".
Qin Shi Huangdi’s necropolis complex was constructed to serve as an imperial compound or palace. It comprises several offices, halls and other structures and is surrounded by a wall with gateway entrances. The remains of the craftsmen working in the tomb may also be found within its confines, as it is believed they were sealed inside alive to keep them from divulging any secrets about its riches or entrance. It was only fitting, therefore, to have this compound protected by the massive terracotta army interred nearby.
In July 2007 it was determined, using remote sensing technology, that the mausoleum contains a 90-foot tall building built above the tomb, with four stepped walls, each having nine steps. Researchers theorized it was built "for the soul of the emperor to depart.