[GI Joe Fan]

Saint Paul the Apostle founded the Eastern Orthodox Church, whereas Saint Peter founded the Catholic Church.

I refer to them as Saints in the conventional definition since they were both murdered while spreading the Gospel.

[Cronos]

And what is the Eastern Orthodox Church which was founded at least contemporaneously, if not earlier, than the Roman Church ?

Orthodox like Orientals or Assyrians are part of the One Catholic and Apostolic CHurch and hence are part of the "If you are Catholic, you know that your religion was founded in the year 33 by Jesus Christ the Son of God, and it is still the same Church. "

Saint Paul the Apostle founded the Eastern Orthodox Church, whereas Saint Peter founded the Catholic Church.

Incorrect. The Eastern Orthodox Church is a group of many Churches as is the Catholic Church. The Patriarchate of Antioch was also founded by St. Peter, as was Rome, while Alexandria was founded by the Apostle St. Mark the Evangelist. There are Orthodox, Oriental and Catholic Patriarchates of Antioch as of Jerusalem.

The Orthodox Church, like the Oriental and Catholic are groups of Churches that were founded by the Apostles (plural) and trace themselves directly back to Christ. Ditto for the Assyrian Church which traces itself back to St. Thomas and St. Barnabus (in India/Syria and Parthia/Iran/China respectively).

All 4 are part of the One CAtholic and Apostolic Church, all are equally venerable in age and all 4 trace themselves back directly through the Apostles to Christ Himself.