The Mouseion and the Library founded

Probably late in Ptolemy I's reign, a shrine of the Muses with salaried scholars, a covered walk, an exedra and a common dining hall is set up in the palace quarter, on the model of the Mouseion of Aristotle's school at Athens. Beside it, or within it, a royal book collection begins to grow. No ancient source gives the year.

What the evidence supports: No ancient source dates the foundation. Plutarch credits the first Ptolemy with the Mouseion; Athenaeus and the Letter of Aristeas tie the great collecting to the second. Most scholars put the founding late in Ptolemy I's reign and the growth under Ptolemy II.