What were some of the reasons that the Roman Republic began to decline?

Here are some of the reasons why the Republic of Rome began a decline:

With the increase of social inequalities came the protests of the plebs and the legend of the slaves, that is, the Spartans. Conflicts and internal divisions in the field of republican ideals (division of power) and the concentration of power of these generals. For example, civil wars: Silva and Mario, Pompeyo, Octavio, and Marco Antonio. The ruin of small agricultural farmers and their emigration to the cities, especially Rome, was a factor that brought as part of the number of people suitable for the army hand in hand, therefore it was necessary to professionalize the army. The professional legions no longer have allegiance to Rome but to their military chief and use it to satisfy personal and political ambitions. The end of the republic was marked by the victory of Octavio over Marco Antonio. In 27 a. C The Senate granted the maximum victorious powers: imperator, maximum pontifex. Octavio being the first emperor of Rome.