After the Western Empire fell, it remained a high honorary title in the Byzantine Empire. Medieval patrician classes were once again formally defined groups of leading burgess families in many medieval Italian republics, such as Venice and Genoa, and subsequently "patrician" became a vague term used for aristocrats and the higher bourgeoisie in many countries.
According to Livy, the first 100 men appointed as senators by Romulus were referred to as "fathers" (Latin "patres"), and the descendants of those men became the patrician class. According to other opinions, the patricians (patricii) were those who could point to fathers, i.e. those who were members of the clans (gentes) whose members originally comprised the whole citizen body. The patricians were distinct from the plebeians because they had wider political influence, at least in the times of the early Republic. As the middle and late Republic saw this influence stripped, plebeians were granted equal rights on a range of areas, and quotas of officials, including one of the two consulships, were exclusively reserved for plebeians. Although being a patrician remained prestigious, it was of minimal practical importance. Excepting some religious offices, plebeians were able to stand for all the offices that patricians could, and plebeians of the senatorial class were no less wealthy than patricians at the height of the republic.
Patricians historically had more privileges and rights than plebeians. At the beginning of the Republic, patricians were better represented in the Roman assemblies, only patricians could hold political offices, and all priesthoods were closed to non-patricians. There was a belief that patricians communicated better with the Roman gods, so they alone could perform the sacred rites and take the auspices. This view had political consequences, since in the beginning of the year or before a military campaign, Roman magistrates used to consult the gods. Livy reports that the first admission of plebeians into a priestly college happened in 300 BC, when the college of Augurs raised their number from four to nine. After that, plebeians were accepted into the other religious colleges, and by the end of the Republic, only priesthoods with limited political importance, such as the Salii, the Flamines, and the Rex Sacrorum were filled exclusively by patricians.
Very few plebeian names appear in lists of Roman magistrates during the early Republic. Two laws passed during the fourth century BC began the gradual opening of magistrates to the plebeians: the Lex Licinia Sextia of 367 BC, which established the right of plebeians to hold the consulship; and the Genucian Law of 342 BC, which required that at least one of the consuls be a plebeian (although this law was frequently violated for several decades).
Many of the ancient patrician gentes whose members appear in the founding legends of Rome disappeared as Rome acquired its empire, and new plebeian families rose to prominence. A number of patrician families such as the Horatii, Lucretii, Verginii and Menenii rarely appear in positions of importance during the later republic. Many old families had both patrician and plebeian branches, of which the patrician lines frequently faded into obscurity, and were eclipsed by their plebeian namesakes.
The decline accelerated toward the end of the Republic, principally because of the civil wars, from the Social War to the proscriptions of the Triumvirs, which took a heavy toll on them. As a result, several illustrious patrician houses were on the verge of extinction during the 1st century BC, sometimes only surviving through adoptions, such as: