The term "patrician" originally referred to a group of elite families in ancient Rome, including both their natural and adopted members. In the late Roman empire, the class was broadened to include high court officials.
The word "patrician" is derived from the Latin word patricius (plural patricii), which comes from patrēs, the plural of pater ("father"). Pater was the term applied to the original members of the Roman Senate. The word comes down in English as "patrician" from the Middle English patricion, from the Old French patrician. In modern English, the word patrician is generally used to denote a member of the upper class, often with connotations of inherited wealth, elitism, and a sense of noblesse oblige.
Patricians enjoyed special status as Roman citizens. They were better represented in the assemblies. The comitia centuriata, the main legislative body, was divided into 193 voting centuries. The first two classes (which contained largely the patricians) were divided into 98 centuries, a number which was enough to obtain a majority, despite the fact that they were fewer in number. That meant that if the patricians acted in concord, they could always determine the result of the voting of the peoples assembly. So, although it was not forbidden for plebeians to hold magistracies, the patricians dominated the political scene for centuries. Strangely, the founding father of the Roman Republic, Junius Brutus (ancestor of Julius Caesar's assassin) was a plebeian.
In the beginning of the Republic all priesthoods were closed to non-patricians. There was a belief that the Patricians communicated better with the Roman gods, so they only 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 B.C. (Liv. X.7.9) 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 minor priesthoods with little political importance like the Salii, the Flamens and the Rex Sacrorum were exlusivey filled by patricians.
In the list of the names of the Romans who held magistracies (the Fasti), very few plebeian names appear before the 2nd century B.C. The turning point were two laws, the Licinian - Sextian law of 367 B.C. that ascertained the right of plebeians to hold the consulship, and the Genucian law of 342 B.C. that made it compulsory that one at least of the consuls be a plebeian.
Patrician gentes that were ancient and their members were part of the founding legends of Rome, disappeared as Rome started becoming an empire and new (plebeian) families rose to prominence, like the Decii and the Sempronii. Families such as the Horatii, Lucretii, Verginii and Menenii seem to vanish after the 2nd century B.C. Others, such as the Julii reappear only at the end of the Republic. There are some cases where the same gens name was shared by patrician and plebeian clans (for example the Appii Claudii were patricians and the Claudii Marcelli were plebeians).