The Western Jin Dynasty used five kinds of coins from the Cao Wei period, while the Eastern Jin Dynasty used the currency from the Wu Dong period. Think with your toes and you'll know how messy the money was in the Jin Dynasty. On the contrary, the hard currency of gold and silver became a luxury, which led to the unsatisfied market demand, directly accelerated the occurrence of the financial crisis, and was also an important reason for the early death of the Jin Dynasty.
It is said that the military strength of the Song Dynasty was weak, but it was not weak at all. The Northern Song Dynasty has the largest, largest and most technologically advanced army in the world, but the coordination ability between generals and soldiers is poor, and the rigid constraints of political and military systems make it difficult to show their combat effectiveness perfectly. The military strength of the Southern Song Dynasty cannot be described by meat, because the most powerful Mongolian iron hoof in the world took 22 years to destroy Xixia, 25 years to destroy Jin people, and nearly half a century to destroy the Southern Song Dynasty. The weapons and equipment in the Song Dynasty were not bad at all, and heaters such as gunpowder were the first to be used.
Cotton is a common cash crop now, which is widely planted in the north and south of the Yangtze River, but it is a representative of wealth and luxury in the Tang Dynasty and is also planted in gardens. At that time, a kilo of refined cotton produced in the western regions cost 2200 pence. The price of cotton clothes sold to the mainland has doubled, and even Du Fu lamented that he could not afford to wear clothes made of cotton. The reason is very simple, because there was no cotton planting technology in the mainland at that time, and it was not until the Song and Yuan Dynasties that the mainland began to grow cotton on a large scale.