Much of Luoyang's history was revealed only by the rebuilding of the city in the 1950s and by the terracing and irrigation work in the surrounding countryside, which brought to light some sixty sites and a thousand tombs. By 5000 BC this area was already heavily populated - the Neolithic site discovered to the west of Luoyang in 1921, at Yangshao , proved to be just one of a whole series of sites along the Yellow River plain. Luoyang's site is a fine strategic one, guarded on three sides by hills and cut across by four rivers. Bronze-Age Shang-dynasty remains have been found here, but the first real development seems to have been a walled city built by the Zhou around 1000 BC. When their rulers were forced to retreat from Xi'an in 771 BC, this became their capital - tradition claims that Confucius studied here and that Lao Zi was keeper of the archives. Under the Qin emperor and his early Han successors, Xi'an regained its title but later Han emperors (between 25 and 220 AD) were once again obliged to withdraw to Luoyang, building their city east of the Baima Si.

Luoyang's trade and communications with the West along the Silk Road grew rapidly: Buddhism was introduced here in 68 AD; the Imperial College was founded with thirty thousand students and a great library; Cai Lun invented paper; and Zhang Hen, the imperial astronomer, invented the armillary sphere, demonstrating that the Chinese knew the movement of the heavens long before the West.

For a time, in the turbulent years after the fall of the Han, Luoyang remained the capital of a series of dynasties and the centre of Chinese culture. Here the poet Zuo Si wrote a series of poems, The Three Capitals, which were so popular that people copying them caused a paper famine.

When the northern Toba Wei invaders decided to move their capital from Datong into the Chinese heartland, Luoyang was the site they chose, probably because it was believed to be the centre of the world. In 493, at the command of Emperor Xiao Wendi, they moved almost overnight to Luoyang and constructed a new capital. In thirty years it had grown to a city of half a million people, with markets selling goods from all over Asia and with more than 1400 Buddhist temples. The great carvings at Longmen were begun in this period. In 543, at the command of another Wei emperor and even more suddenly than it had been taken up, Luoyang was again abandoned and its people forced to move to Yeh . An account written thirteen years later described the city walls in a state of collapse and overgrown with artemisia, the streets full of thorn trees, and millet planted between the ceremonial towers of the ruined palace.

Luoyang lay in ruins once more for seventy years until under the Sui dynasty it was rebuilt west of the Wei ruins on a grid pattern spreading across both banks of the Luo River. Two million men were conscripted for the work, and the new city rapidly became the most important market centre in China, a magnet for foreign traders, with a population of a million, three separate major markets within the walls, more than three thousand shops and stalls and around four hundred inns for merchants. To feed the crowds, grain was brought up the Grand Canal from the Yangzi basin and stored in enormous barns: the Hanjia granary, discovered in 1971 west of the old city, held 250,000 tons and protected against damp, mildew, rats and insects. Emperor Yang Di also brought three thousand musicians to live at court and surrounded himself with scholars, scientists and engineers.

Under the Tang , Luoyang was only the secondary capital. It's said that in 800 AD Empress Wu Zetian, enraged that the peonies , alone among flowers, disobeyed her command to bloom in the snow, banished them from her capital at Chang'an. Many were transplanted to Luoyang where they flourished, and have since become one of the city's most celebrated attractions, the subject of countless poems and cultivation notes. Several times drought forced the court to follow the peonies to Luoyang, where the empress commissioned some of the most important carvings at Longmen.

With the decline of the Tang, Luoyang finally lost its importance for good; the capital moved to Kaifeng , and gradually the whole balance of the nation shifted south. Luoyang never recovered, and by 1920 there was only a run-down settlement of some twenty thousand people here. The first Five Year Plan earmarked the city for industrial development , and its new incarnation has not looked back since. Growth has been rapid ever since the early 1950s, helped by a position astride the east-west rail line and the southern spur to Yichang. Once again Luoyang is a thriving metropolis, if a lot less attractive and more polluted than the city of old.