other · 290 · Caesarea Maritima
Pamphilus was a wealthy presbyter of Caesarea who had studied at Alexandria and came home to look after Origen's books. What he built out of them was not a private collection but a working scriptorium: manuscripts collated and corrected, copies of the scriptures written out in his own hand and given to whoever wanted them, and a catalogue. Jerome, who used it a century later, says he was so devoted to books that he transcribed most of Origen himself. The library is the physical precondition of this dataset. Eusebius wrote the Ecclesiastical History in it and out of it, the Hexapla survived there long enough to be described, and the great biblical codices of the fourth century are associated with it. Nothing dates its founding, so the year here is a placing inside his Caesarean years.
To keep and correct books — and to give them away, which he did constantly, to anyone who would read them.
The library of Caesarea, and therefore the Ecclesiastical History, the Hexapla's survival, and most of what anyone knows about the first three centuries.