Bronze production is the achievement of a certain level of human development and civilization. Large works of bronze were produced as early as the late-Xia dynasty (the Erlitou period, ca. 1900 - ca. 1500 BCE). By the time of the early-Shang dynasty (the Erligang period, ca. 1500 - ca. 1300 BCE) and the late-Shang period (the Yinxu period, ca. 1300 – ca. 1028 BCE), early Chinese smiths produced large quantities of imposing works with intricate designs. The Qing imperial treasury acquired a large quantity of bronzes, and, by the time of the Qianlong Emperor, their collection included several thousands of works. In 1949, some of the works were transported to Taiwan while others were lost. The remaining works have been preserved by the Palace Museum. Since the establishment of the People’s Republic of China, the Museum’s collection has greatly increased due to government allocations, private donations, and acquisition by purchase. The collection currently includes over 15,000 works of bronze from throughout Chinese dynastic history. Notably, approximately 10,000 articles in the collection date from before the Qin dynasty (221-207 BCE). The Palace Museum thus has the largest holdings of bronzes in all of China.