THE business acumen of the astute merchants of Shanxi has been legendary since the Song dynasty a thousand years ago. By the Ming and Qing dynasties, these Jinshang as they were called, controlled much of the trade in north China. They also set up the country's first banks at Pingyao and with their great wealth, built magnificent walled residences with multiple courtyards and hundreds of rooms.

Who can forget the scene in director Zhang Yimou's 1992 classic Raise the Red Lantern, where Gong Li and the other wives of the manor wait silent and expectant at the gate to their respective courtyards for the red lanterns that announce the arrival of their lord? Or, like a caged bird, the concubine singing on the mansion's ramparts?

Director Zhang's dramatisation of Su Tong's novella by the same name was so evocative that the movie was nominated for an Oscar and immediately propelled both the mansion and Gong Li to international fame.

The manor, or perhaps more appropriately, castle where Gong Li and the other bored and tormented fictional concubines lived as virtual prisoners was in reality once home to one of Shanxi's richest Jinshang families, the Qiaos of Qixian county, a dusty rural district about 60km south of Shanxi's provincial capital Taiyuan.

Begun in the mid-18th century, the Qiao courtyard residence (Qiaojia dayuan) is a maze covering nearly 9,000sq m and completed only in the early 20th century.

The layout of the more than two dozen courtyards and 313 rooms is said to be in the shape of the Chinese character for shuangxi, meaning double happiness. Although the interiors are now shabby, the elaborate roofs, solid brick walls and finely painted panels and carvings that decorate the doorways leave no doubt as to the great wealth of the Qiaos.

The Qiao mansion is a fine example of northern Chinese residential architecture.

Conversely, the family "treasures" are, to put it mildly, bizarre and perhaps reflect the family's rustic taste. I was struck dumb by the large crystal orbs, a heavy screen with zealously-carved panels best described as baroque, and most of all by a pair of grubby lanterns hanging from the ceiling that looked like giant ossified spiders. It was hard to reconcile the masterly architecture of the manor with these outlandish souvenirs.

Qiaojia dayuan's long passageways and imposing grey walls, some 10m high, felt claustrophobic after a while. They were obviously meant not only to keep intruders out but also to keep the inhabitants in. No wonder Gong Li's character in Raise the Red Lantern eventually went mad from ennui.

One would never have guessed that the great wealth of the Qiaos was built on the humble soybean from which beancurd is made. Like many other Shanxi merchants, the Qiao patriarch headed north to trade and set up a soybean business in Baotou, Inner Mongolia, which became the family's business base.

They subsequently increased their products to include items like tea and of course expanded into that Jinshang specialty, banking. The family fortunes reached new heights in the 19th century under Qiao Zhiyong, whose story is fictionalised in the 2006 TV series Qiaojia dayuan.

It was not easy to work for a family as commercially-powerful as the Qiaos. In one of the halls, a list of requirements stated that clerks had to be "tall, handsome, virtuous, capable and kind". This may seem peculiar, but with the exception of tall and handsome, the other qualities hark back to the Confucian values closely-embraced by all Shanxi's Jinshang and indeed by merchants from other provinces as well.

At Kaifeng, the ancient capital on the Yellow River, there is a Shan-Shaan-Gan guildhall jointly shared in the past by merchants from the provinces of Shanxi, Shaanxi and Gansu. Just inside the courtyard gate stands a screen wall emblazoned with the merchants' Confucian creed - "zhong, ren, yi" - loyalty, benevolence and righteousness.

These values formed the basis of the trust placed by people who did business with the Jinshang and are unquestionably a key reason for their success through the centuries. The Qiao residence was packed with local tourists the day we were there and perhaps inevitably, there are increasing signs of commercialisation. The pleasant back garden, complete with costume rental office, is evidently a popular spot for wedding photos. Zhang Yimou's red lanterns (there are none in the original novella) have also been copiously hung in the courtyards in obvious reference to his famous movie.

Qiaojia dayuan's size makes it seem more like an enclosed village with interconnected courtyards than a single residence, but our guide Mina said it is "small" compared to the Wang family mansion which has 1,118 rooms and 123 courtyards spread over an area four to five times the size of the Qiao manor.

Some of these mansions have been turned into money-making tourist attractions. Regardless of the motives, I was relieved to see that the courtyard residences of Shanxi's Jinshang are still around for all to enjoy.