The correct order is monarchy, republic, oligarchy and dictatorship
Ancient Rome has known various forms of government. In the monarchy the form of government adopted in Rome until VI a.C, the Romans believed that the king had a divine origin.
At the beginning of the Republic, Roman society was divided into 4 classes: Patricians, Clients, Plebeians and Slaves.
The political, social and economic decadence caused the plebs to enter into conflict with the patricians, this struggle lasted about 200 years.
In the oligarchy, the representatives had so many powers they gave him several privileges: his statues were placed in the temples and the emperors happened to be venerated like a god. An example was (Jupiter Julius) that it was the emperor Julius Caesar that went until 44 a.C when it was assassinated.
The dictatorial period lasted from 110 BA to 79 BA was marked by political persecution to followers of the previous government. With the political support of the patricians, the Roman Senate regained its power and authority.