You know, Tibet is located in the cold winter of the Qinghai-Tibet Plateau. Although they wanted to March into Tibet during the Qin and Han Dynasties, it was a pity that the people in the Central Plains were prone to altitude sickness and the mountains and rivers were far away, so they gave up territorial expansion. The Qinghai-Tibet Plateau has also become a geographical barrier for the southwest expansion of the Central Plains Dynasty.
During the Sui and Tang Dynasties, Tibet moved from decentralization to unification. The leader Songzan Gambo succeeded to the throne after he was thirteen years old, and then unified all the tribes in Tibet and established a unified slave country, namely the Tubo Kingdom. Because Tibetans have always lived as nomads, they have to face the harsh natural environment during their growth. Natural warriors are tall, brave and have strong fighting capacity.
The powerful Tubo also had several military conflicts with the Tang Dynasty. In the fight, they both found each other difficult to provoke and could not take advantage of each other. As a result, Princess Wencheng entered Tibet and kissed her, which brought a brief peace to the Tang Dynasty and Tibet. After the death of Songtsan Gampo and Princess Wencheng, Tubo also fought for the western regions. At that time, the Tang dynasty could not completely defeat Tibet, nor did it completely unify Tubo. On the contrary, both the Yuan Dynasty and the Qing Dynasty easily entered the Qinghai-Tibet Plateau and unified Tubo. What is the reason?
In fact, it is not that Datang is not strong enough, but the climate is also an important reason. According to the research of Mr. Zhu Kezhen, the founder of modern meteorology in China, the temperature in the ancient world reached a very special warming period in the ninth century. Due to the rising temperature, the snowy areas and wasteland with an average elevation of about 4 kilometers on the Qinghai-Tibet Plateau at that time were all plateau pastures with rich aquatic plants. Due to the development of animal husbandry, it also stimulated the growth of population and the strength of the Tubo kingdom. Therefore, the Tubo Kingdom occupied the strategic Hexi Corridor, threatening the rule of the Tang Dynasty. ?
During the Yuan Dynasty and the Qing Dynasty, the world temperature was also falling, and the East Asian continent and other plain areas may not be greatly affected by the temperature drop. However, due to the cold climate, the Qinghai-Tibet Plateau lost its lush grasslands and farmland, and was covered with ice and snow in the world of ice and snow. Because there was no animal husbandry as the basis, the Tubo dynasty also declined, and in the face of the invasion of nomadic cavalry such as the Yuan Dynasty and the Qing Dynasty, it could only choose to surrender.
At the same time, the introduction of Tibetan Buddhism played a role in reducing the fighting capacity of Tibetans. Since the ninth century, the Tubo kingdom has been caught in a battle for imperial power. Due to the separatist regime of military commanders, Tibetan people are suffering from frequent civil strife. At this time, the introduction of Songzan Gambu into Tibetan Buddhism also played a calming role. Most people converted to Buddhism, resulting in the idea of banning killing and advocating peace, which made them no longer aggressive towards Tubo. This is also an important reason why in the Yuan, Ming and Qing Dynasties when Tibetan Buddhism prevailed, Tubo was easily brought into the rule of the Central Plains dynasty.