This area has been the site of some of the oldest cities in the world's oldest civilization. Its history begins in the Bronze Age, three thousand years ago, when the western Zhou dynasty, known for their skilled bronzework, built their capital at Fenghao , a few miles west. Nearby, one of their chariot burials has been excavated. When Fenghao was sacked by northwestern tribes, the Zhou moved downriver to Luoyang and, as their empire continued to disintegrate into warring chiefdoms, the nearby Qin kingdom expanded. In 221 BC the larger-than-life Qin Shi Huang united the Chinese in a single empire, the Qin, with its capital at Xianyang , just north of Xi'an. The underground Terracotta Army , intended to guard his tomb, are this tyrant's inadvertent gift to today's tourist prosperity.

His successors, the Han, also based here, ruled from 206 BC to 220 AD. Near contemporaries of Imperial Rome, they ruled an empire of comparable size and power. Here in Xi'an was the start of the Silk Road, along which, among many other things, Chinese silk was carried to dress Roman senators and their wives at the court of Augustus. There was also a brisk trade with south and west Asia; Han China was an outward-looking empire. The emperors built themselves a new, splendid and cosmopolitan capital a few miles northwest of Xi'an which they called Chang'an - Eternal Peace. Its size reflected the power of their empire, and records say that its walls were 17km round with twelve great gates. When their dynasty fell, Chang'an was destroyed. Their tombs remain, though, including Emperor Wudi's mound at Mao Ling .

It was not until 589 that the Sui dynasty reunited the warring kingdoms into a new empire, but their dynasty hardly lasted longer than the time it took to build a new capital near Xi'an called Da Xingcheng - Great Prosperity. The Tang, who replaced them in 618, took over their capital, overlaying it with their own buildings. This city was in its day the capital of a great empire and one of the biggest conurbations in the world, with more than a million people housed in a magnificent city whose plan was so rational that it was taken as the model for the building of many other Chinese cities and for the Japanese capital, Nara, in 710. The huge rectangle enclosed by walls nearly 10km long was divided by further walls into 108 districts, crisscrossed by a grid plan of streets. These walled-in quarters had no communication with each other except by a single gate which led to the main street; the gates were closed at sunset and reopened at dawn. Only top officials were allowed doors giving directly on to the street. The preoccupation with order and compartmentalizing society became even more apparent in the Imperial City, enclosed by more walls, and the palace, further enclosed, inside that.

The Tang period was a golden age for the arts, and ceramics, calligraphy, painting and poetry all reached new heights. You can get some idea of the quality from the Tang horses and camels in Xi'an's Shaanxi History Museum, the Classics of Filial Piety in the Forest of Steles, the wall paintings in the Tang tombs and the relics buried as offerings to the Buddha's fingerbone in the Famen Si. The Roman glassware found here testifies to the flourishing trade along the Silk Road at the time, as do the many foreign coins in the museum. The open society was reflected in its religious tolerance - not only was this a great period for Buddhism, with monks at the Jianfu Si busy translating the sutras the adventurous monk Xuan Zong had brought back from India, but the city's Great Mosque dates from the Tang, and one of the steles in the Provincial Museum bears witness to the founding of a chapel by Nestorian Christians.

After the fall of the Tang, Xi'an went into a long decline . It was never again the imperial capital, though the Ming emperor Hong Wu rebuilt the city as a gift for his son; today's great walls and gates date from this time. Occasionally, though, the city did continue to provide a footnote to history. When the Empress Dowager Cixi had to flee Beijing after the Boxer Rebellion, she set up her court here for two years. In 1911, during the uprising against the Manchu Qing dynasty, the Manchu quarter in Xi'an was destroyed and the Manchus massacred. And in 1936, Chiang Kaishek was arrested at Huaqing Hot Springs nearby in what became known as the Xi'an Incident.