Which role played a more important role in the history of the Tang Dynasty, Chang'an or Luoyang?

Luoyang and Xi'an had an important position and respective influence in the history of the Tang Dynasty. From the current perspective, of course Luoyang played a greater role.

The capital of the Tang Dynasty was Chang'an in the early days of the Tang Dynasty, because Chang'an had geographical advantages and was a military pass: "According to the stronghold of Weihan, it supports Yongzhou", "It blocks mountains and rivers, and is a land of four fortresses!" "Chang'an is surrounded by Tongguan in the east, Dashanguan in the west, Wuguan in the south, and Xiaoguan in the north. The four passes control the passage in and out of Chang'an. They are easy to defend but difficult to attack, and their geographical location is very important.

But Changan faces a big problem: lack of food. The Tang government had no choice but to requisition grain from the area south of the Yangtze River. Although there was a canal, the transportation distance was long and took a long time, and the risk was also high. Once there was a violent storm, the ship might capsize in the canal.

Luoyang has two major advantages. First, water conservancy advantages. As we all know, during the period of Emperor Yang of the Sui Dynasty, in order to facilitate patrols and entertainment, he built a new capital, Luoyang, in the south of the Yangtze River, and dug a grand canal to divert water from the north to the south. Although the dissolute and shameless Emperor Yang of Sui later became a slave of the country, the opening of the Grand Canal made the exchanges between Luoyang and Chang'an closer. By strengthening the flow of trade, Luoyang's economic development can be described as rapid and rapid. The second is the advantage of grain and grass. At that time, Luoyang had a mountain of food because of the Luokou granary.

It is precisely because of this that when Emperor Gaozong of the Tang Dynasty, in order to solve the food crisis, he often took civil and military officials to Luoyang to "eat for free". Later, Emperor Gaozong of the Tang Dynasty began to improve the status of Luoyang, officially designated it as the eastern capital, built the Luoyang Palace, and called Chang'an and Luoyang the "East and West Houses". Luoyang's legal status as the vice-capital was thus determined.

During the period of Wu Zetian, she made a bolder decision to position Luoyang as the real capital of the empire and renamed it the "Divine Capital", surpassing Chang'an in status. From then on, she stayed in Luoyang and rarely returned to Chang'an. Government agencies were also moved to Luoyang.

After the fall of Wu Zetian, Tang Zhongzong moved the power back to Chang'an, but Luoyang was still a very important capital. When Xuanzong of the Tang Dynasty, he actually spent one-third of his time in power in Luoyang. Every time I go to Luoyang, it’s because of food problems.

Later, a minister named Pei Yaoqing improved the water transportation process and greatly increased the speed of transporting grain from the south of the Yangtze River. Chang'an's grain shortage was finally solved.

Chang'an's lofty status has been unbreakable since then, but Luoyang remains prosperous and has become a real flower in the south of the Yangtze River.