In Ancient Rome, the plebs were the general body of Roman citizens, distinct from the privileged class of the patricians. A member of the plebs was known as a plebeian (Latin: plebeius). The term is used more commonly today to refer to one who is in the middle or lower class, or who appears to be; however, in Rome, plebeians could become quite wealthy and influential.
Ancient tale
The true origin of the distinction between plebeians and patricians is unknown; there is little evidence for any sort of ethnic basis, nor many signs of a distinction during the time of the kings. However, the populace of the city of Rome during the reigns of Romulus, Numa Pompilius, and Tullus Hostilius were all called patrician as they were the only inhabitants of Rome. It is during the reign of Ancus Marcius that the plebeians came to Rome from diplomatic alliances as secondary citizens. In any case, around the time of the foundation of the Roman Republic, the plebeians were excluded from religious col
Source:
http://en.wikipedia.org/wiki/Plebs