The central location of Chang'an (today, Xian) in what is now Shaanxi Province near the confluence of the Wei and Feng Rivers helps explain why the area was the location of several important imperial capitals for about a millennium of Chinese history. The first really unified Chinese empire, that of the Qin, had its capital just north of the current city. Although the Qin emperor failed to establish a lasting dynasty (he died in 210 BCE), in some ways he is the Chinese ruler best known outside of China because of his massive tomb complex with its models of more than 8000 soldiers and their horses, spread over some 56 square kilometers. Its discovery in the 1970s was arguably the most important archaeological find of the twentieth century. Recent work on some of the other Chinese imperial tombs in the area provides a tantalizing hint of spectacular finds to come over the next decades.
The Han dynasty succeeded the Qin, initially chose Luoyang to the East as its capital, but then in 202-200 BCE to the south of the Qin capital began construction of Chang-an, "the first great city in Chinese history." It was under Emperor Wu Di (141-87 BCE) that the first Chinese missions were sent to Inner Asia, an event considered to mark the beginning of the Silk Road. He substantially expanded the capital with the erection of many new palaces, but the glory of Chang'an came to an end in 24 CE during the disorders connected with the collapse of the Former Han dynasty. The city was looted and burned and subsequently fell to the status of simply a provincial city when subsequent rulers chose Luoyang as their capital. A poem written in the year 292 evokes the desolation of the city:
Street wards are deserted and desolate;
Town dwellings are sparsely scattered.
The buildings and offices, stations and bureaus,
Shops and markets, official storehouses,
Are now concentrated on a single corner of the wall--
Of a hundred, barely one survives...
Great bells have fallen in the ruined temple;
Bell frames have collapsed and suspend no more...
[Xiong, pp. 15-16]
Chang'an revived in the fourth century, once more the capital, and witnessed a cultural florescence in part thanks to the fact that it became a center of Buddhist learning. Several important Buddhist pilgrims and translators resided there around the beginning of the fifth century, among them Faxian, who traveled to India, and the scholar Kumarajiva. The revival came to an end in civil strife, and for over a century after a conquering army took the city in 417, it ceased to be the capital. A brief revival in the second half of the sixth century ended abruptly with the accession of the Sui dynasty in 581, since the first Sui emperor decided to build an entirely new city to the south of Han Chang'an and on the exact location of the modern Xian. The choice of the site and the layout of the city were in part determined by divination with reference to astrological signs.
The city continued to be the principal capital of the empire and entered the greatest period of its development under the Tang Dynasty (618-907). "At the height of its glory in the mid-eighth century, Chang'an was the most populous, cosmopolitan, and civilized city in the world" (Richard B. Mather, foreword to Xiong, p. ix), occupying some 84 sq. km. with around one million inhabitants. It suffered major damage during the An Lushan rebellion in the mid-8th century, but even toward the end of the Tang period, when the empire was in disarray, the "enormous size" of the city impressed an Arab visitor.
Under the Tang, the city was a major religious center, not only for Buddhism and Taoism but also for several religions which were relatively recent arrivals in China: Zoroastrianism, Nestorianism and Manichaeism. The most famous of all the Buddhist pilgrims, Xuanzang, had to sneak out of Chang'an in 629, but by his return in 645 would be greeted by a huge throng. Apart from the remarkable feat of his journey, his great accomplishment was to bring back copies of the Indian scriptures that he spent his remaining days translating. One of the few major Era-era buildings left in Xian today is the Big Wild Goose (Dayan) Pagoda, first built in 652 in the Daci'en Monastery to house the library Xuanzang collected (the current structure was re-built in 701-704). Even in a period when persecution of Buddhism had begun, a Japanese pilgrim noted in 844 that there were over 300 Buddhist temples in Chang'an.
The spread of the new religions can be documented fairly specifically. A stele (inscribed stone pillar) erected in 781 relates the introduction of Nestorian Christianity as early as 635 by Syrian priests. Zoroastrianism received some impetus when the last of the Sassanian (Iranian) princes Firuz took refuge in China in the 670s, having fled the Arab invasions. Manichaeism also was connected with the arrival of Persians at the Tang court as early as 694. It really flourished though only after the An Lushan rebellion, when the Tang dynasty was saved by the support of the Manichaean Uighurs. All of these religions (and Buddhism as well) suffered from religious persecutions initiated in 845.
With the collapse of the Tang at the beginning of the tenth century, Chang'an decayed rapidly. However, it continued to play a role in the western trade and experienced a revival under the Ming beginning in the late fourteenth century. The southern gate (Nan Men) was built in 1370-1373. The bell tower (Zong Lou) located at the intersection of the main north-south streets in the exact center of the walled part of the city was built in 1384 (and then rebuilt several times). The city still preserves something of its former cosmopolitan culture, notably in its large Muslim community. The Great Mosque (Qingzhen Dasi) was first built in 742, but the structures one sees to day date largely are no earlier than the late Ming.
--Daniel C. Waugh
Victor Cunrui Xiong, Sui-Tang Chang'an: A Study in the Urban History of Medieval China (Ann Arbor: Center for Chinese Studies, The University of Michigan, 2000).