When it comes to the history of ancient feudal dynasties, the first impression is that it lasted a long time. In the course of so many years of historical development and change, there have been many dynasties, accompanied by the change of political power. As dynasties changed, rulers generally made changes in their choice of capital. Xi'an was developed from Chang'an, but today's Xi'an is no longer as prosperous as it was when it was the capital. When the Tang Dynasty and previous dynasties chose Chang'an as their capital, the appearance of Chang'an at that time was completely different from that of Xi'an today.
Today's barrenness contrasts sharply with the prosperity and richness of the past, and the beautiful wetness. Once Xi'an, the climate was very humid, the precipitation was abundant, the sunshine was also very good, many people regarded this place as a treasure of feng shui, which is why the Western Zhou Dynasty until the Tang Dynasty was the capital here. However, after the Tang Dynasty, the climate here has changed greatly, the climate has changed from warm and humid to dry and rainy, and accompanied by wind and sand, which makes the ecological environment in this area even worse. Originally, Chang'an had a pleasant climate, because it was the capital of the Central Plains Dynasty, so it attracted many people to settle down. As the climate has become harsher and the land is severely water-scarce, it is no longer suitable for large-scale cultivation of crops. Without a supply of basic food crops, people's daily lives become increasingly difficult.
In fact, during the Sui Dynasty, Chang'an began to gradually become dry and rainy. To this end, the rulers also gathered a large number of laborers to dig canals, but compared with the consequences of climate change, the construction of canals is undoubtedly a symptom rather than a cure, and later, it has not had much substantive effect. Even if more effort was made to transport grain from the south to Chang'an, it would not be able to meet the needs of the people here. So over time, the living conditions here become more and more unsustainable.
By the time of the Tang Dynasty, although the capital was still in Xi'an, the actual office of the emperor had already moved to Luoyang, which is why we can often see in the film and television dramas where Wu Zetian was in power, and officials and emperors often stayed in Luoyang. As for the later dynasties, Chang'an was even less suitable as a capital at that time, such a city that once had a period of prosperity, because of the climate, lost its former glory.
From another point of view, a city has always been the capital of all dynasties, and such a situation is rare. Rulers often consider various factors when choosing a capital. The reason why the dynasties before the Tang Dynasty chose to be in Chang'an Dingdu was related to the territory of the Central Plains Dynasty at that time. At that time, the territory of the Central Plains Dynasty had not yet expanded to the northeast, or even if it did, it did not take this area as a key jurisdiction area, so that the capital city was selected in the east, which was not conducive to the jurisdiction of the Central Plains. The rulers did not set the capital in the south, because the south had not yet been effectively developed.
Even in the Tang Dynasty, the southern region was not fully exploited. Dynasties in history were very dependent on agriculture, and the area where Chang'an was located was an important grain producing area when the original climate was humid, and there were also some factors in this regard. In any case, the choice of a capital city does not significantly affect the rise and fall of a dynasty. Although the later Yuan, Ming, and Qing dynasties have always used Beijing as the capital, these three dynasties have perished. As for Xi'an, a city that has lost its advantage due to natural reasons, it is even more understandable that the rulers did not choose it as the capital.
(Image from the Internet)