Nader Shah, who ruled Iran from 1736–47, conquered parts of Pakistan, Turkey, and Iraq. He started the Afsharid Dynasty, which ruled until 1750. They were replaced by the short-lived Zand dynasty.
In 1925, the Qajar dynasty was overthrown by Reza Khan, the father of Mohammad Reza Pahlavi. Reza Khan was overthrown by the USSR in World War II.
In 1951, Mossadegh was elected prime minister. In 1953 (where the video conveniently starts), Mossadegh was overthrown by Reza Pahlavi, son of the old monarch, in a US-sponosred coup.
As you can see, Iran has a very violent history. The myth of a "peaceful Iran" dies here.