Book 3 — Chapter 21 - Cerdon, Third Ruler of Alexandria
Book III carries the narrative through the destruction of Yerushalayim, the post-apostolic successions, Domitian, Trajan, early writings, and Eusebius's catalogue of accepted and disputed texts. He synchronizes local leadership with imperial reigns, using successions at Rome, Alexandria, Antioch, and Yerushalayim as chronological anchors. These notices are institutional claims from his sources, not proof that every later title or jurisdiction existed in identical form from the beginning. In this reconstruction the chapter coordinate is preserved as Book 3, Chapter 21, and the full subject is retained under the heading 'Cerdon, Third Ruler of Alexandria'. Names, dates, quoted-source relationships, and political or textual function are kept distinct from Eusebius's own interpretive claims.