In general a patriarch is the father and ruler of a family or tribe. He is regarded as a venerable personage possessing wisdom and ability to direct and guide those who are dependent on him for leadership. So were the patriarchs of the Old Testament, such as Abraham, Issac and Jacob.

In ecclesiastical history and terminology, patriarch was the name given to the bishops of ancient and venerable sees, which held a position of primacy and had authority over the bishops of the neighbouring provinces.

The original patriarchates were three, namely, that of the West, held by the bishop of Rome, and those of Alexandria and Antioch. The First Council of Nicaea (325) recognizes an ancient, customary and legitimate authority in the bishops of these 3 areas, although the title of 'patriarch' was not yet applied to them. The title came into use in the 5th century. Earlier it had been used loosely for the bishop of any great see.

While the primacy of the Bishop of Rome stands out, 'patriarch' is the highest grade in the hierarchy of ecclesiastical jurisdiction, the others, after the patriarch being primate, metropolitan (archbishop) and suffragans.

From the latter part of the 4th century, Constantinople became the 4th patriarchate, and from 451 Jerusalem became the 5th. Thus, by the middle of the 5th century, there were five patriarchates, those of Rome, Alexandria, Antioch, Constantinople and Jerusalem.

Countries to the west of the Balkans came under the authority of the patriarch of the West, the Bishop of Rome who as successor of St Peter held the unique position of head of the universal Church. Constantinople ruled most of the Byzantine Empire. Syria and Mesopotamia came under Antioch, Palestine under Jerusalem and Egypt under Alexandria.

Schism and the emergence of 'Orthodox' Churches led to separation from Rome of the other four patriarchates, which have thereafter functioned independently. The patriarch is the head of each of the Orthodox Churches.

The Holy See recognizes several patriarchates in the Eastern Churches that are in communion with it. Thus there is a Maronite, Melchite, and a Syrian patriarch of Antioch, a patriarch of Cilicia of the Armenians, a Coptic patriarch of Alexandria and a patriarch of Babylon of the Chaldaic rite.

As stated above, the Pope is the patriarch of the Western Church, but four minor patriarchates also exist in the West, the bishops of which are called 'Patriarch' largely as a title of honour. With the spread of the faith in the West and the East, along with the colonial expansion of the two Catholic nations of the Iberian Peninsula (Spain and Portugal), two sees rose to prominence in relation to the overseas expansion of the Church. Their bishops were given the title of patriarch. Thus we have a patriarch of the West Indies who is the prelate of the highest rank in the Church of Spain, and a patriarch of the East Indies, who is the Archbishop of Goa. The other two patriarchs of the Western Church are the patriarchs of Lisbon and Venice.