How did Buddhism evolve within Tibet?

In Tibet, there was an early translation period and later translation period. Because of the problems and difficulties within the Buddhist community, within the spirit of Buddhism in Tibet, there are two historical waves of Buddhism. 

We have four main schools of Buddhism in Tibet, and most of them belong to the later spread of Buddhism.

The lineage of Kagyu came within the later spread of Buddhism.

HH 17^th Karmapa
Ogyen Trinley Dorje

From Kamashila
Short-Ngon-dro teaching
Germany, 2014