First of all, we must emphasize that datang at that time was really powerful and really brilliant, whether it was military or political or even cultural, it was the top level in the entire world at that time, and its status was by no means inferior to that of the current world hegemon, the United States, or even more so. At that time, the Tang Dynasty was brilliant, glorious, and powerful, and all nations came to congratulate and all nations came to the dynasty, which was the peak of the glory of the Han people!
After Li Longji overthrew the rule of Wu Zetian's "Wu family", Emperor Gaozong Li Zhichan was located in Li Longji, known in history as Tang Xuanzong, because the entire Tang Dynasty under his rule was politically clear, the economy was prosperous, and the entire Tang Dynasty reached a peak, so it was also called "Tang Ming Emperor". (It is also the name of Xuan Ye in order to avoid the name of the Kangxi Emperor in later generations)
Li Longji was a very diligent emperor at the beginning, and he corrected the chaos and reused the sages, at that time the politics were clear, the economy was rapidly restored and more rapid development and prosperity, and soon reached a peak, known in history as the "Kaiyuan Prosperous Era"!
The history books record that (Xuanzong) was born wise and decisive, knew the rhythm of music, and had a majestic and handsome appearance.
However, the Tang Dynasty reached its peak in the hands of Emperor Xuanzong, but it also took a sharp turn for the worse because of him. In fact, we can understand it from three aspects:
First, the Tang Emperor laxated his administration. Since the development of the Tang Dynasty to the peak, Emperor Xuanzong seems to have lost his goal, no longer has the ambition of his youth, nor does he have the heart to strive for excellence, but instead focuses on pleasure, no longer has the enterprising heart, and does not have the heart to govern this prosperous world.
Second, foreign relatives are involved in government affairs, and party struggles are constant. The scourge of the Tang Dynasty began with civil strife, but it also failed. Emperor Xuanzong favored Yang Guifei exclusively, reused the Yang family's people (Yang Guozhong), and added to the traitor Li Linfu's control of the imperial government, which was inseparable from the literati party at that time. When everyone is thinking about fame and fortune, then the dynasty has begun to decline.
Third, the feudal towns were divided, and the moderation made the power too great. Tang Xuanzong had a very bad thing to do, he actually set up local envoys to govern the border troubles, which was a very big policy mistake, he actually thought of reusing An Lushan and other ethnic groups outside the Country to try to stabilize the tang Dynasty's frontiers, to know that "not my race, its heart will be different", which eventually caused the eight-year-long Anshi chaos, the entire Tang dynasty national strength and material resources were almost hollowed out, and from then on it was devastated, and it was no longer glorious.
Emperor Xuanzong created the glory of the Tang Dynasty, but it also led to the decline of the Tang Dynasty, right and wrong, who can comment? In this regard, do you think that Li Longji has done more than he has done, or has he done too much? Welcome to discuss below~