Short answers, pulled from the story.
The ancient city of Yotkan served as the capital of the Kingdom of Khotan. Water from the Yurung-kàsh and Kara-kàsh rivers combined with sediment from the Kunlun Mountains created fertile land for agriculture in an otherwise arid climate.
Khotanese Saka became the recognized official court language by the tenth century. Rulers used this Eastern Iranian language alongside Gandhari Prakrit for administrative documentation.
Chinese pilgrim Faxian visited the kingdom in 399 AD. He reported on fourteen large viharas, many small ones, and an active Buddhist community within the city.
Hundreds of jade pieces found in the tomb of Fuhao originated from Khotan and appeared in Anyang royal tombs dating to 1200 BC. This trade allowed the kingdom to hold influence over surrounding regions for centuries.
The An Lushan Rebellion started in 755 AD and weakened Tang control significantly. The city fell under the Tibetan Empire again in 792 after being lost completely during that period.
Muslim Kara-Khanid ruler Yusuf Qadir Khan conquered Khotan in 1006. A long war ensued between Islamic Kashgar and Buddhist Khotan beginning around 934 AD when Satuq Bughra Khan converted to Islam.