Three patriarchates were established by the apostles as apostolic sees in the 1st century: Rome, Antioch, and Alexandria. Added to these were Constantinople in the 4th century, and Jerusalem in the 5th century. Eventually, together, these five were recognised as the pentarchy by the Council of Ephesus in 431.
In the rest of the history of Christianity, a few other patriarchates were gradually recognised by any of these above ancient episcopal sees. With time, eventually some of them fell due to military occupations following the Islamic conquests of the Middle East and North Africa, and became titular or honorary patriarchates with no actual institutional jurisdiction on the original site.