Bronze is an alloy of copper and tin with lower melting point and a higher degree of hardness than those of copper. When it is cast, bronze has the advantages of minimum air bubble production and maximum flow quality and can produce objects with razor-sharp edges or exquisite decoration, thus making it a suitable material for durable weapons, tools, and containers. China employed bronze objects as long as four thousand years ago in the period of the Longshan culture and brought the use of bronze ceremonial vessels to a peak in the Shang (c.1600-1046 BC) and Zhou (1045-256 BC) dynasties.
The spiritual practices of the Shang dynasty people arose from the belief that the spirits of ancestors in the supernatural world were forever in control of man's earthly well-being, and it was therefore necessary that offerings of prayer and food constantly be made to them. From the evidence of oracle bone inscriptions we know that not only did the people of the Shang dynasty offer sacrifices to a wide range of phenomena, but their ceremonies were varied and complex. The vessels used by the ruling house and nobility to offer food or wine in these sacrificial ceremonies were cast of bronze. Their types were extremely varied; many had their origin in everyday objects of pottery or wood.
Bronze ritual vessels were often cast with extraordinary kinds of engraved decoration. Whether expressing the religious aspirations of the Shang people or reflecting aspects of the lives of the Zhou people in the earthly realm, they are able to capture for us the spirit of the times that produced them. It was also customary to cast inscriptions in bronze ritual vessels to record some recognition of meritorious achievement, bestowal of imperial favor, appointment to office, settlement of a contract, proclamation of a new statute, taking of an oath, or other such occasion. Documents on bamboo strips or classics written on silk from the pre-Han period have been reduced to ashes by the ravages of time, and only the inscriptions on bronze vessels have come down to us as one kind of contemporaneous record of so ancient period of history.
In Western Asia, the Sumerians were already familiar with the "lost-wax process" or casting bronze vessels by the middle of the third millennium BC. The Bronze Age in China may thus be said to have arrived comparatively late, but the “piece-mold process” borrowed from indigenous pottery production methods in the Neolithic period developed independently.
The bronze vessels that have survived from the Shang and Zhou dynasties were by no means handed down from generation to generation right down to the present. Rather, they emerged at one time or another from the ancient tombs or storage pits in which they had been buried. Sometimes topsoil would become eroded after a heavy rainstorm or washed away by the flow of a river, forcing the earth to give up its treasures, or perhaps ancient vessels might have turned up accidentally when peasants plowing a field or excavating a well uncovered an ancient tomb. Because a tomb is essentially a storage place for precious objects, there have been those who have excavated graves in search of treasure. In fact, ever since the early Western Zhou dynasty, there has never been a time when grave-robbing was unknown. Of the bronze vessels of the Shang, Zhou, Qin, and Han dynasties that have emerged from tombs, some have been scattered into the hands of collectors, where they have been devotedly maintained, and some have been assembled within the inner court of the imperial palace, where they have been preserved and cataloged. Concepts of connoisseurship among people of former times were different from those of today. Collectors often used to take the soiled and rusted curios they acquired out of the earth and grind them down or pick out the bits of green mottled oxidation and cover the outside with wax. These kind of "doctored" objects are commonly called shukeng (熟坑), or "soiled excavated objects.”
Other ancient civilizations of the world, such as Egypt and Assyria, have left majestic architectural and sculptural ruins for people to admire, while China's legacy of ancient greatness is her bronze ritual vessels. Harmonizing form, decoration, engraving, and inscriptions, Chinese bronzes epitomize the highest level of technological and artistic expression in ancient times. They furthermore can be spoken of in socio-political terms, for it was society and politics that, because of the role bronze ritual vessels played within them, were the impetus behind the development and evolution of bronze art.
[Based on articles from the National Palace Museum in Taipei.]