As stated earlier it is likely that glaze was first observed by Chinese potters as an accident of firing when a fall of ash onto the top of a pot in a kiln fused with the clay to produce a “kiln glost” or patch of glaze covering, because of the fortuitous presence of minerals in the ash. The early development of high-fired glazes in China during the Shang Dynasty can probably be ascribed to a deliberate attempt to mimic kiln glost in a controllable way. The glazes were lead-free, made up of wood ash, feldspar and kaolin in roughly equal proportions, and fused at temperatures between 1100 and 1200 degrees C. The glaze had a thin yellowish colour, although very few examples still exist. During the excavation of Anyang, a small quantity of vessels was found covered with this thin, hard, yellowish/green, evenly applied glaze that was applied in liquid form to the body. This is the earliest recorded discovery of high-fired glaze (approximately 1,500 BC). The body of these particular vessels was fired at a higher temperature than the blackware, but probably not high enough to be “true” stoneware. The kilns used for these examples were believed to have been of the previous “non-downdraught” form, but still managed to achieve a high temperature and reducing atmosphere by careful firing control.

8.12 Shu Dynasty

There was a further surprise in the 1980’s in Sanxingdui near Chengdu in Sichuan Province, well west of the previously supposed cultural centres. Another significant culture active around 1,300-1,200 BC, called the Shu, was known to have lived in this area and at various times they were at war with the Shang. What was unearthed during excavation of what turned out to be one of the Shu’s major cities showed that they were highly developed and had unique pottery and bronzes that were found in sacrificial pits. In this culture though, the pits were filled with artefacts rather than the human sacrifices practised by the Shang. These finds illustrate that there are still potential surprises because of the size of China and the diversity of its cultures.

8.13 Zhou (Chou) Dynasty (1046-256 BC)

Map of Zhou Dynasty - courtesy Thomas
Lessman, worldhistorymaps.info

The Shang Dynasty ended in tyranny and chaos as the Zhou tribes from the Northwest penetrated Shang territory and spread widely. Although for some time the Zhou had co-existed with the Shang, and there was intermarriage and cultural exchanges, it is thought that they were being driven from their home farmlands by Northern Nomads, so they in turn moved into the Wei River area near Xian in Shaanxi Province. They started off with one walled city, Hao-ching, but within three generations, by 1046 BC, they had taken over completely from the Shang. The Zhou were happy to take over the Shang culture and add it to their own traditions.

When the Zhou had overthrown the Shang, they set up a feudal system under the Zhou leader as king, and he carved up the land for his closest followers. Again the king was supreme Feudal Lord and Spiritual Leader, but his real power over those in control of the various states is not clear. As the power of the various Feudal Lords rose, central control declined.

Early Western Zhou pottery continued the Shang tradition with the production of hard stoneware, although the white pottery disappeared. Decoration included incised animals, especially rampant tigers, on wheel-made dark-grey wares. Glaze developed in various unconnected parts of China at this time. A group of tombs just north of old Lo-yang, Henan Province, dated to 10^th to 9^th century BC, revealed stoneware vessels with a greyish-white to grey/green glaze, well covered and thicker than in the Shang period. The body was fine-grained kaolinic clay, when fired at 1200 degrees C had very little water absorption and was relatively thin. About 100 years later at T’un-hsi, Anhui Province two tombs revealed hand-made wares with the rims, feet and decoration finished on a wheel, and potters marks roughly scratched onto their bases. Some had brown iron oxide glaze poorly matched to the body, causing flaking, and uneven from brush application but others with less iron in the glaze and applied by dipping were of good quality, with a hard glassy smooth surface and pale greyish/ green colour achieved by careful kiln reduction, possibly using an improved Shang-type kiln. Examples of both types were popular and widely distributed, suggesting they were valuable items of trade. As some of the richest finds of high-fired, glazed pottery was not from Henan, but Anhui Province, it showed that the centre for advanced ceramic technology was moving South East with the growth of population to the lower Huai and Yangtze valleys.

Glass has also been found in the Zhou period, as beads in tombs dated to 900-800 BC. Some might have been imported from West Asia, but it was also probably an independent by-product of pottery glaze