Why is the dalai Lama in exile?

Recently, Lady Gaga and the Dalai Lama appeared together at a conference in the U.S. on Sunday to talk about the benefits of compassion.
Compassion is something I have been talking a lot about in my posts, so this story grabbed my attention. I also really like Lady Gaga. (cannot wait for American Horror Story 6!!)
Their discussion was based around this ideal: "Hope is essential to keep the world going."
CNN reported that Gaga has angered her Chinese fans in meeting with the Dalai Lama and that her music may have a ban placed on it because of this. 

Clearly- there is no freedom in China.

A government banning a nationwide pop idol? And a people forced to back that decision? It's an interesting topic for discussion.

The Dalai Lama is the religious and political leader of Tibet.

The current Dalai Lama was exiled from Tibet in 1959 after a failed Tibetan uprising against the Chinese occupation. He led the Tibetan government-in-exile for many years but has since passed his political authority to democratic institutions.

In occupied Tibet, any sign of loyalty to the Dalai Lama can be met with arrests, lengthy sentences, torture, violent crackdowns and 're-education' programs. Despite more than 50 years of China's oppressive occupation, Tibetans remain fiercely loyal to their spiritual leader.

After years of guerrilla war between Tibetan rebels and the Chinese soldiers in a land that China considered to be its territory, the Chinese still see him as a huge threat to their country,