Why is King Tutankhamun one of the most famous pharaohs in spite of the fact that he played such as small role in the history of Egypt?

Well, first he is the youngest Egyptian pharaoh and he died after 10 years of ruling in mysterious conditions. He also restored the old Egyptian religion and his tomb was found completely intact, in difference to other tombs which were either destroyed because of their age or robbed.

He was the first pharaohs to be a boy