While individual plebeians, or freeborn Roman citizens outside the patrician, senatorial and equestrian classes, were able to gain economic power by amassing wealth and joining the equestrian class, their chances of joining the politically influential senatorial class were extremely remote. Collectively, however, plebeians were able to effect political and social change by forming a mob and rebelling against their social superiors.
Social climbing was difficult for plebeians and, even for members of the equestrian class, entering public office as a senator was unlikely. This is because political power in ancient Rome was reserved for an elite minority.
Plebeians wishing to apply for formal membership in the equestrian class, or equites, were required to prove that their assets amounted to 400,000 sesterces or more. Membership to the senatorial class required assets in excess of 1,000,000 sesterces. However, most senators were also nobles, that is, people with a family history of consulship. Cicero was one of the few equestrians to become a senator and consul.
It was common for members of the equestrian class to invest in land and plantations or farms, which increased their power significantly. However, their business activities were often overseen by senatorial governors, and their power thereby kept in check. Equestrians were distinguished from senators by their tunics, which bore narrower stripes.