I want to know the answer to the following question:
What was the name of the agreement between Britain and the Chinese that kept the British out of Tibet?
All the background I'm provided with is that "During The Great Game era, taking advantage of the Dungan revolt in northwest China, Yaqub Beg invaded Xinjiang from Central Asia with support from the British Empire, and made himself the ruler of the kingdom of Kashgaria.". Is that enough to answer the question?
Answer: no