How did plebeians gain power in the republic?

The Conflict of the Orders between patricians (the aristocracy) and plebeians (the commoners, both rich and poor) had two strands. It started with a rebellion of the poor plebeians. The grievances of the poor plebeians were economic, primarily indebtedness, the interest rates of loans and insufficient land for the peasants. The rich plebeians became the leaders of the movement and also had another agenda: power-sharing with the patricians. The patricians monopolised political power by monopolising the seats of the senate and the consulship (the office of the two annually elected heads of the Republic).

The rich plebeians used the agitations of the plebeian movement to fight for power-sharing with the patricians and to gain access to the consulship and other offices of state which were created as the Republic developed and to the seats of the senate. They achieved this and were co-opted into a patrician-plebeian oligarchy. They also were given equite (cavalryman) status. The equites were the second highest rank of Roman society. At this point the rich plebeians turned their back on the poor, whose economic grievances were never addressed properly.