foundation · 43 · Alexandria
Eusebius says Mark was the first sent to Egypt to preach the gospel he had also committed to writing, and the first to found churches at Alexandria itself (HE 2.16). Everything downstream in this dataset's Alexandrian line rests on it: Anianus succeeds him, the numbering runs unbroken to the present Coptic pope, and the see's claim to rank beside Rome and Antioch is an apostolic claim made through Mark. The tradition is not attested before Eusebius and the Coptic sources are later still — but the tenure was already in this dataset from ordinal 1 with no event under it, which meant a succession line began out of nothing.
To carry the gospel to Egypt.
A see whose patriarchs are still counted from him, and one of the four great lines of this dataset.