From the time of Tang Gaozong, the Tang Dynasty moved from Chang 'an to Luoyang from time to time, and then moved back to Chang 'an after a while. Every migration is not only costly, but also causes great confusion. After Emperor Xuanzong of the Tang Dynasty ascended the throne, the imperial court exchanged more frequently between Chang 'an and Luoyang. According to the Book of the Old Tang Dynasty, from the fifth year of Kaiyuan (7 17) to the twenty-fourth year of Kaiyuan (736), Xuanzong of the Tang Dynasty made as many as ten trips with officials of civil and military affairs, almost once every two years. Then the question is, why is Tang Xuanzong so keen on going back and forth between Chang 'an and Luoyang?
In fact, the reason for this is not that Tang Xuanzong likes fooling around, but that the real environment forces him to do so.
First of all, although Chang 'an is located in the grain-producing area of Guanzhong Plain, with the continuous expansion of the city scale and the sharp increase of population, the grain output of Guanzhong Plain has been unable to feed more and more people. If you want to transport grain from other places to Chang 'an, because of the inconvenient transportation, it will cause huge transportation costs. On the contrary, Luoyang is surrounded by an intricate network of canals and canals, and is at the hub of the Grand Canal, with extremely convenient traffic conditions. The grain produced in the south can be directly transported to Luoyang by water, which is both economical and efficient.
Secondly, at the beginning of the eighth century, the Guanzhong Plain was not peaceful. 7 1 1 year, a major earthquake occurred in the fenshui river basin of Hedong. 7 12 long-term drought in spring and summer; In 7 12 ~ 7 13, severe famine occurred in Weishui River Basin and Gyeonggi area. Serious drought in July14. The constant emergence of various disasters has made Chang 'an's living environment even worse.
In addition, with the increasing military establishment in Guanzhong and Northwest China, the food supply in Chang 'an is even worse.
In the fifth year of Kaiyuan (7 17), on the tenth day of the first month, Emperor Xuanzong of the Tang Dynasty moved the imperial court to Luoyang and lived there until the winter of 7 18. In the next 20 years, Emperor Xuanzong spent 9 years in Luoyang. Frequent migration not only costs a lot, but also seriously interferes with daily government affairs. So why didn't Emperor Xuanzong of the Tang Dynasty simply move the capital to Luoyang? In fact, this also has his difficulties.
Chang 'an is the "base camp" of the military nobles in Guanzhong and Northwest China, and also the power base camp of the Li royal family. Although the emperor is nominally the son of heaven, in fact he is just like ordinary people. The reason why the emperor can command the world depends on the support of a large group of nobles who hold real power around him. If you lose these followers, then the emperor is no different from ordinary people. Therefore, in order to solve the food crisis, Emperor Xuanzong of Tang Dynasty was forced to move the capital to Luoyang, but as long as the situation improved slightly, he had to return to Chang 'an with Manchu officials to consolidate his political position.
So, has the "relocation" dilemma of Emperor Xuanzong of the Tang Dynasty really become an inextricable knot? Actually, it is not.
In the 21st year of the reign of Emperor Xuanzong of the Tang Dynasty (733), a minister named Pei Yaoqing was appointed as the prime minister (assistant minister of Huangmen, secretary of Pingzhang of Tongzhong Shumen), who was also the grain envoy of Jianghuai and Henan, and was fully responsible for the grain transportation of the Yellow River. Pei Yaoqing had in-depth research on grain transportation in his early years, and now he is a hero in this position. Under his reform, it is no longer the responsibility of the local authorities to collect grain from the junction of the Canal and the Yellow River to the granary in Shi Jing. This not only saves the transportation time of local grain transporters, but also reduces the cost of paying local authorities to transport grain. Grain is transported to Chang 'an station by station along the Yellow River and Weishui River. At the end of each station, the grain is stored in a transfer bin so as to be transported to the next station at an appropriate time. There are a large number of grain depots in Yin He, Zhou Bei and Luoyang in the northern plain. At the right time, from Jin Meng to Hexi, the whole transportation efficiency is greatly improved.
In just three years, Pei Yaoqing has accumulated 7 million stone grain and rice for the country through the reform of grain transportation, saving 300,000 tons of freight. Since then, the food supply problem in Chang 'an, which troubled several emperors in the Tang Dynasty, has finally been completely solved. Therefore, after returning to Chang 'an on October 21st in the 24th year of Kaiyuan (736), Emperor Xuanzong of the Tang Dynasty settled down for a long time and was forced to "move" without begging.
References: Old Tang Books and New Tang Books.