consul, -lis
An official of the Roman state. In the period of the Republic, it was the highest military and political office: two consuls were elected each year. The consular office survived into the Imperial period (and further into the early Byzantine period), becoming a honorary post.

senator, the (1. Roman, 2. Byzantine)
1. A Roman body of men that originally advised the king and then the consuls; Heredity was not the only means of joining the senate and “new men” or novi homines could become part of it; Augustus revised the senate and left the body with less power and bolstered hereditary claims as a means to enter the senate; it continued to make laws and conferred powers on new emperors.2. Member of the senate. The senate, a roman institution transferred from Rome to Constantinople by Constantine I during the Byzantine period was an advisory body whose rights and responsibilities were not clearly defined. It was consisted of imperial officers coming from the upper and were ranked according to hierarchical levels: viri illustri (perfectus praetoriae and the magister), viri spectabili (proconsul, vicarius and the comes), viri clarissimi (consul praetoriae) and viri perfectissimi (praeses and duces). Since the 6th c. AD a new title was established for the upper officers (viri gloriosi). The years that followed officials were entitled to officers regardless their position as senators or if they were about to be admitted to this body.

tribune, the (tribunus plebis)
Officer responsible for the security of the lower classes.(plebs). His office was inviolate and ο tribunus had the right to exercise veto on the decisions of other officers (dictators were an exception). During the Roman Democratical time, there were ten tribuni plebis. However, when Augustus became an emperor he included the tribunicia potestas (the tribunus' power) in his responsibilities.