In traditional China north was felt to be the least favourable of the cardinal directions. Its mythic guardian spirit was the black-green tortoise, frighteningly entwined with a snake in a coiled embrace. It was the imagined location of the Yellow Springs, the subterranean region where spirits of the human dead dwelt under the frozen winter soil while awaiting re-birth. North was also the direction from which barbarian invaders were most likely to come and ruin the idealised peace and prosperity of the Middle Kingdom.

Gilt bronze belt plaque from the OrdosNorthern China was enclosed within the supposed protection of the Great Wall and extended from the Gulf of Bohai in the east to the margins of the Taklamakan Desert in the west. It included the arid regions of Inner Mongolia and the Ordos desert of northern Shaanxi, which imperial governments had much difficulty in defending against the scorned and feared barbarians. In fact those same 'barbarians', who made light of the Wall as a line of defence, actually made significant contributions to both the territorial extent of China and its art.

From 398 to 494 the Turkic peoples of the Toba Wei dynasty set up their capital at modern Datong, Shanxi province. In the nearby cliffs, on the orders of the 'barbarian' emperors, huge statues of the Buddhas were hewn out of the stone in dozens of cave temples. The largest surviving figure today is fifteen metres high, and the Yungang grottoes, as they are known, are one of China's greatest artistic treasures.

Helingeel tomb entranceAt the other end of the scale, measuring no more than a few centimetres, are examples of craftsmanship in bronze decorated with scenes typical of the flora and fauna of the Ordos. In the early centuries CE this was far richer than it is now, but a severe climatic change in the 11th century saw temperatures fall across northern China, which lost much of the vegetation and many of the creatures it had previously enjoyed. Among the early bronze animals from this region are deer, rams, camels and tigers. Murals on the walls of a 2nd-century CE tomb at Helingeer, in Inner Mongolia, depict the kind of farming activities that were once practised where today there is nothing but grassland.

The Mongols incorporated the Middle Kingdom into their own empire when they completed its conquest in 1279, and built their capital at Cambaluq (modern Beijing ). Though they themselves were soon driven from power, something of their artistic legacy lived on, and is still to be seen in the splendid White Dagoba in Beihai Park, a tribute to the Lamaist religiosity of Kublai Khan.

Farming scene: Helingeer tomb muralMountain and desert cover much of north China, but to the south-west of Beijing, across Hebei and eastern Shanxi provinces, stretches the North China Plain, commonly known as the Great Plain. This fertile, low-lying agricultural land is shaped like a giant funnel pointing from Manchuria into the heart of central China, and down it poured the last foreigners to invade China, the Manchus. Easily crushing the Chinese defences, they captured Beijing in 1644 and established the Qing dynasty. Their contribution to the shape of modern China was immense, extending it once and for all beyond the Great Wall. They incorporated into it the western territories of Xinjiang and Tibet; the vast northern expanses of Mongolia (including modern Inner Mongolia province and what is now the People's Republic of Mongolia. This was formerly known as Outer Mongolia until with the connivance of the Soviet Union it claimed independence from China in 1924); and the north-eastern provinces now known as Manchuria.

The cold, unattractive north may have seemed less than appealing. Ironically, however, in a simplistic conception of the country divided into north and south, northern Chinese saw themselves as superior to southerners from below the Yangzi, and generally still do. It was, so northerners claimed, from their half of the country that the civilisation of the old central states had spread south to embrace the whole empire.