I want to know the answer to the following question:
When was the Mongol-Tibetan alliance started?
All the background I'm provided with is that "The Wanli Emperor (r. 1572–1620) made attempts to reestablish Sino-Tibetan relations after the Mongol-Tibetan alliance initiated in 1578, which affected the foreign policy of the subsequent Qing dynasty (1644–1912) of China in their support for the Dalai Lama of the Gelug school.". Is that enough to answer the question?
Answer: yes