1) 1000 million years ago there was a single mass of land Pangia and a single water body panthalsa.
2) the land was divided into two parts called Gondwana and Angara land by Tethy sea
the plates got further divided into more plates the two of them were Eurasian and Indo-Australian plate
3) these two plates collided
4) the collision was convergent the sediments of tethy sea got deposit
5) the deposition of sediments resulted in formation of Himalayas