The claim, perhaps, was modest. Beijing's recorded history goes back a little over three millennia, to beginnings as a trading centre for Mongols, Koreans and local Chinese tribes. Its predominance, however, dates to the mid-thirteenth century, and the formation of Mongol China under Genghis and later Kublai Khan . It was Kublai who took control of the city in 1264, and who properly established it as a capital, replacing the earlier power centres of Luoyang and Xi'an. Marco Polo visited him here, working for a while in the city, and was clearly impressed with the level of sophistication:

So great a number of houses and of people, no man could tell the number I believe there is no place in the world to which so many merchants come, and dearer things, and of greater value and more strange, come into this town from all sides than to any city in the world

The wealth came from the city's position at the start of the Silk Road and Polo described "over a thousand carts loaded with silk" arriving "almost each day", ready for the journey west out of China. And it set a precedent in terms of style and grandeur for the Khans, later known as emperors, with Kublai building himself a palace of astonishing proportions, walled on all sides and approached by great marble stairways.

With the accession of the Ming dynasty , who defeated the Mongols in 1368, the capital temporarily shifted to present-day Nanjing, but Yongle, the second Ming emperor, returned, building around him prototypes of the city's two greatest monuments - the Imperial Palace and Temple of Heaven. It was in Yongle's reign, too, that the basic city plan took shape, rigidly symmetrical, extending in squares and rectangles from the palace and inner-city grid to the suburbs, much as it is today.

Subsequent, post-Ming history is dominated by the rise and eventual collapse of the Manchus - the Qing dynasty , northerners who ruled China from Beijing from 1644 to the beginning of the twentieth century. The capital was at its most prosperous in the first half of the eighteenth century, the period in which the Qing constructed the legendary Summer Palace - the world's most extraordinary royal garden, with two hundred pavilions, temples and palaces, and immense artificial lakes and hills - to the north of the city. With the central Imperial Palace, this was the focus of endowment and the symbol of Chinese wealth and power. However, in 1860, the Opium Wars brought British and French troops to the walls of the capital, and the Summer Palace was first looted and then burned by the British, more or less entirely to the ground.

While the imperial court lived apart, within what was essentially a separate walled city, conditions for the civilian population, in the capital's suburbs, were starkly different. Kang Youwei, a Cantonese visiting in 1895, described this dual world:

No matter where you look, the place is covered with beggars. The homeless and the old, the crippled and the sick with no one to care for them, fall dead on the roads. This happens every day. And the coaches of the great officials rumble past them continuously.

The indifference, rooted according to Kang in officials throughout the city, spread from the top down. From 1884, using funds meant for the modernization of the nation's navy, the empress Dowager Cixi had begun building a new Summer Palace of her own. The empress's project was really the last grand gesture of imperial architecture and patronage - and like its model was also badly burned by foreign troops, in another outbreak of the Opium War in 1900. By this time, with successive waves of occupation by foreign troops, the empire and the imperial capital were near collapse. The Manchus abdicated in 1911, leaving the Northern Capital to be ruled by warlords. In 1928 it came under the military dictatorship of Chiang Kaishek's Guomindang , being seized by the Japanese in 1939, and at the end of World War II the city was controlled by an alliance of Guomindang troops and American marines.

The Communists took Beijing in January 1949, nine months before Chiang Kaishek's flight to Taiwan assured final victory. The rebuilding of the capital , and the erasing of symbols of the previous regimes, was an early priority. The city that Mao Zedong inherited for the Chinese people was in most ways primitive. Imperial laws had banned the building of houses higher than the official buildings and palaces, so virtually nothing was more than one storey high. The roads, although straight and uniform, were narrow and congested, and there was scarcely any industry. The new plans aimed to reverse all except the city's sense of ordered planning, with Tian'anmen Square at its heart - and initially, through the early 1950s, their inspiration was Soviet, with an emphasis on heavy industry and a series of poor-quality high-rise housing programmes.

In the zest to be free from the past and create a modern, people's capital, much of Old Peking was destroyed , or co-opted: the Temple of Cultivated Wisdom became a wire factory and the Temple of the God of Fire produced electric lightbulbs. In the 1940s there were eight thousand temples and monuments in the city; by the 1960s there were only around a hundred and fifty. Even the city walls and gates, relics mostly of the Ming era, were pulled down and their place taken by ring roads and avenues.

Much of the city's contemporary planning policy was disastrous, creating more problems than it solved. Most of the traditional courtyard houses which were seen to encourage individualism were destroyed. In their place went anonymous concrete buildings, often with inadequate sanitation and little running water. In 1969, when massive restoration was needed above ground, Mao instead launched a campaign to build a network of subterranean tunnels as shelter in case of war. Built by hand, millions of man-hours went into constructing a useless labyrinth that would be no defence against modern bombs and served only to lower the city's water table. After the destruction of all the capital's dogs in 1950, it was the turn of sparrows in 1956. A measure designed to preserve grain, its only effect was to lead to an increase in the insect population. To combat this, all the grass was pulled up, which in turn led to dust storms in the windy winter months. Recent years have seen an attempt to do battle with some of the worst pollution, and factories that can't modernize have been closed. The city's open spaces have been revitalized with a massive tree-planting campaign. And to help with problems of overcrowding, there are ambitious plans for a series of satellite cities. Now the city's main problem is its traffic - car ownership has rocketed, contributing to the appalling air quality, and the streets are nearing gridlock.