Who had complete control in ancient Rome?

Answer 1

This depends on the time of history we are talking about. During the 2544 years of the Kingdom (753-509 BC) the kings had complete control.

The 482 years of the Roman Republic (509 BC-27 BC) Rome was headed by two annually elected consuls. By the Mid Republic the Senate became the most powerful political body because it was the only body capable to co-ordinate the military campaign of imperial expansion and the administration of the conquered territories. In 82 BC Sulla became dictator for one year. This was an extraordinary officer of state which was appointed by senatorial decree to deal with an emergency whose term of office was six months. Unusually, Sulla was given a term of one year, during which he executed thousands of political opponents. When Julius Caesar became the most powerful man in Rome he had himself appointed dictator for one year, then for ten year and then for life. However, he was assassinated.

Augustus won the last civil wars which led to the downfall of the Republic, became the first Roman Emperor and established rule by emperors which lasted 503 years (27 BC-476 AD).