potentate
Peter the Great was a king in the sense that he was an autocratic ruler such as a monarch. He was not a king in the sense that he was crowned "Czar" as opposed to "King."
Nobody this person would be called a dictator.
He was the last Tsar (Former Emperor of All Russia) . He was a husband of Alexandra. He was an autocratic monarch or ruler who was forced to abdicate his throne.
Yes Stalin was an autocratic ruler. He let power get into his head as he was supreme ruler.
The ruler of a country is typically referred to as the head of state or the monarch in a monarchy.
monarch
unlimited.
An autocratic ruler has got unlimited power and usually does not allow, not even formally, that others than himself and a close follower group have a say in the government.
A ruler that has unlimited power and authority over his or her power is an absolute monarch.
monarch
Monarch is a ruler. It's like a king or a queen.