The Yangzi Jiang is often known in Chinese simply as Jiang ('The River'), or as Changjiang, ('Long River'). Above Chongqing its name changes to Golden Sand (Jinsha) River, and as it crosses the lofty Tibetan plateau and nears its source in Qinghai province it is known as the Way to Heaven (Tongtian) River. 3,964 miles from source to mouth, it is one of the world's longest rivers. Together with its hundreds of feeder rivers it has been of enormous value to the agricultural economy of central China and to water-borne communication, mainly between west and east. However, it is prone to serious flooding during the monsoon season of June to September. The worst recorded disaster was in 1931, when 140,000 people drowned and Nanjing was under water for six weeks, but every year brings fresh tragedy. The river is also fast flowing and wide, and despite the benefits it has to offer, it has traditionally been a great barrier to north-south communication. Not until 1957 was it first bridged, at Wuhan.

A Han Dynasty wild boarIn traditional China the land to the south of the Yangzi River was commonly called Jiangnan ('South of the River'), and was generally regarded by those living further north as being beyond the pale. Even as late as the Tang dynasty, links with the north could be difficult and problematic, and it continued to be regarded as somewhere strange and even semi-barbarian. It was a place of exile for government ministers fallen from grace. The idea supported by some modern historians, that the inhabitants of the south-east coastal region (between modern Zhejiang and Guangxi provinces) had been the very first to cultivate rice, and had cultural links with peoples far across South-East Asia would have been greeted with incomprehension.

The southern climate was hotter and wetter than that in the north. The flora and fauna were more exotic. The Han were outnumbered by many other ethnic groups, who spoke different languages, wore different clothes, ate different food and built their houses differently. The inhabitants of south China were the most likely to emigrate, especially to South-East Asia and, in the second half of the 20th century, to the West.

South China was the region where rebellion was most liable to erupt, a tendency which was exacerbated by the arrival in China of the alien ideas and habits of the Western powers. It was in Guangxi province that the Taiping Rebellion, a pseudo-Christian and anti-dynastic movement, erupted in 1850. Its leader, Hong Xiuqan, was a Hakka. The Hakkas ('Guest People') were an ethnic group who had migrated from the north several centuries earlier, and had never fully integrated with the native peoples of Guangxi and Guangdong provinces. By the time the rebellion was put down in 1864 as many as thirty million lay dead, and much of southern China was in ruins.

On the other hand, it was south China that provided many of the empire's essential raw materials, like silver, salt, coal, and iron, and the prized commodities of tea and porcelain. Its tax revenues were principally assessed in quantities of the staple crop, rice, but the tax barges sailing north up the Grand Canal also carried silk and sometimes even slaves. The metropolitan areas of the north also relied on Jiangnan for supplies of exotica such as camphor wood and peacock feathers, some of which arrived at the southern seaports from parts of south-east Asia and beyond.

The southern landscape varied from the wide, flat reaches of the Pearl River delta in Guangdong province to the famous sugar-loaf peaks, the vertical mountains beloved of many artists, which were a distinctive and unusual feature of Guizhou province. Softer hillsides, especially in the south-east, were covered in tea bushes and orange trees, while others were terraced to support rice paddies. Its great lakes were a source of food and centres of communication, commerce, and recreation.

In the south-west, the fertile, mountain-locked basin of Sichuan constituted such a rich economic zone that its population level was always among the densest in the empire. Its remoteness and difficulty of access at the head of the Yangzi gorges gave it a degree of potential independence from the rest of the country. During World War Two, while other parts of China endured the Japanese occupation, the Guomindang government of Chiang Kai-shek evacuated its capital to Chongqing and the province preserved its parlous independence. Not ten years later, after the establishment of the People's Republic of China, the Maoist authorities in Beijing were accusing the governor of Sichuan, Li Jingqan, of ruling the province as a private kingdom.

Further down into the remote south-west, the dense jungles of mountainous Yunnan (meaning 'To the south of the clouds') were home not only to elephants, tigers, and fierce wild boar, but also non-Han tribes who could be equally unwelcoming to officials and armies from further north. There, on the Sino-Burmese border, a British diplomat, Augustus Margary, was murdered in 1875, provoking an international incident following which the first ever Chinese overseas embassy was established (in London, 1877).

An example of Chu woodworkRegional cultures across southern China were as varied as the physical features. In the 17th century, society in the sophisticated 'Jiangnan cities' of the Yangzi delta contributed to the great literary and painting output of that period. Their tastes and preferences were still those associated with mainstream Han interests and traditions, and they not only matched but even outshone the intellectual and artistic achievements of their northern neighbours.

A traveller going west, however, could hardly be unaware that he was entering 'alien' territory. By the time he had sailed half way up the Yangzi he was in the heartland of what had once been the state of Chu. In the Warring States period its arts were particularly bold and colourful, quite different from those of the central states to the north. Nearly forty years into the early Han period, when it had been incorporated into the newly united empire, the coffins of the feudal rulers the Marquis and Marchioness of Dai, buried at Mawangdui in c.168 BCE, were still decorated and furnished in distinctive styles with overtones of the shamanism that prevailed there. Two of the coffins were covered with silk banners painted with scenes that may have been intended to guide the departing souls upwards to heaven, spiritual route-maps. And lest it be believed (as many northerners were no doubt still prone to do) that the south was intellectually backward, along with other paintings and books buried with the coffins were maps of the physical geography of the region, the oldest discovered anywhere in China.

As he approached the entrance to Sichuan, the traveller was penetrating the remote vastnesses of ancient Ba and Shu. Among the cultural characteristics of Ba were its unique boat-shaped coffins, and the practice of 'hanging' coffins high up on seemingly unscaleable cliff sides along the Yangzi Gorges. Inside the Gorges, the enormous bronze sculptures found in royal burial sites of the Shang period at Sanxingdui in 1989 are evidence for the independence of Shu art forms.

Braving the mountain trails into the isolated communities of Yunnan, the traveller would have found there social habits and cultural preferences that owed as much to neighbouring states such as Shan (modern Burma, or Myanmar) and Annam (Vietnam) as to China. In particular, the people here had and still have a great love of elaborate and colourful jewellery.