Battle of Talas
The Battle of Talas took place in 751 AD at the Talas River in modern-day Kyrgyzstan. It was fought between the armies of the Arab Abbasid Caliphate and the Tang Dynasty of China. The Arab victory marked the easternmost expansion of the early Islamic empire. The Tang Dynasty, which was already facing internal unrest, lost the confidence of the local tribes and thus was never able to reassert its influence in Central Asia. This lead to the spread of Islam in what would become Afghanistan, Pakistan, and Turkmenistan. China would not regain its foothold Central Asia (with the exception of the brief Yuan Dynasty hold during the 1300s) until the Qing Dynasty reconquered it in a series of battles against the Muslim tribesmen in the 18th century.
It is also believed by historians that the Chinese knowledge of papermaking was learned by the Arabs after capturing two Chinese papermakers during the battle. The knowledge made its way west, with evidence of a paper mill in Baghdad by the 790s, from which it then reached the Mediterranean Sea and Europe as a whole.