The Heirloom Seal of the Realm (), also known in English as the Imperial Seal of China, was a Chinese jade seal carved out of the Heshibi, a sacred piece of jade. The Seal was created in 221 BC, shortly after Qin Shi Huang unified China and established the Qin dynasty, China's first imperial dynasty. The Heirloom Seal served as the imperial Chinese seal throughout the next millennium of Chinese history, and its possession was seen as a physical symbol of the Mandate of Heaven. The Heirloom Seal was lost around the end of the Tang dynasty (618–907) or during the Five Dynasties and Ten Kingdoms period (907–960). Creation In 221 BC, the Seal was created when Qin Shi Huang destroyed the remaining Warring States and united China under the Qin Dynasty. Heshibi was a famous piece of jade stone which previously belonged to the Zhao state. Passing into the hands of the new Emperor of China, he ordered it made into his Imperial seal. The words, "Having received the Mandate from Heaven, may (the emperor) lead a long and prosperous life." (受命於天, 既壽永昌) were written by Prime Minister Li Si, and carved onto the seal by Sun Shou. The Seal was carved from jade because, in ancient China, jade was symbolic of the inner beauty within humans. Many tombs and burials from ancient China contained decorative jade, including a jade burial suit unearthed in 1968 that belonged to a Han prince, Liu Sheng. During the Han dynasty, the Chinese associated jade with immortality to a point where some individuals attempted to drink jade in liquid form to gain eternal life. This association further complements the idea of the Mandate of Heaven and why the Seal was carved in jade, China's most valued material for thousands of years. The Romance of the Three Kingdoms says that Liu Bang, who became the first Han emperor, saw a Phoenix sitting on a rock and presented the rock to Xiang Yu, the king of Chu, who split the stone in two with his sword and found the jade with which the seal was carved. Han dynasty and Three Kingdoms period At the death of the second Emperor of Qin, his successor Ziying proffered the Seal to the new emperor of the Han dynasty, whereafter it was known as the "Han Heirloom Seal of the Realm". At the end of the Western Han dynasty