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Eratosthenes is appointed to the Alexandrian library under Ptolemy III as later lives report

Dated 31 December 244: Eratosthenes is appointed to the Alexandrian library under Ptolemy III as later lives report. In the causal graph this event strengthens Digital Learning Access, a driver that weakens Learning Poverty Rate (low- and middle-income countries) — an improving welfare path.

Sources: [1][2]

Read the full account

Handbook years cluster around the 240s BCE. He did not file a 21st-century library URL. Callimachus and Apollonius remain named predecessors in the same later file.

Context

The Mouseion-and-library was a Ptolemaic court institution. Shared work with unnamed copyists, the king’s officers, and later reporters is the point. Elite lock-in of royal books is not invented here as a second twin of the same office.

Eratosthenes’s documented role is bounded by other offices and collaborators named in the sources below.

Conventional years are c.276–c.194 BCE. Almost no autograph survives. Cleomedes, Strabo, Nicomachus, and later encyclopedias are the public file. Classroom globe reconstructions are not his acts. Contribution is complex.

Why it matters

It is not a modern open-stack statute and not a recovered shelf-list autograph.

Who was responsible

Contribution type and responsibility level for each recorded actor — not sole-author shorthand.

  • Eratosthenes

    Person

    Direct responsibility

    responsibility level 0.4 · verified

What changed

Fact → Driver → Indicator. Relationship strength orders the paths; it is not the observed indicator movement.

Evidence

The sources behind this fact and its verification state.

Verified2 sources on file
  1. 1.Britannica — EratosthenesEncyclopaedia Britannica · High credibility · verified
  2. 2.MacTutor — Eratosthenes of CyreneUniversity of St Andrews · High credibility · verified
What the sources establish

MacTutor and Britannica print a received appointment of Eratosthenes as librarian at Alexandria under Ptolemy III Euergetes after study in Cyrene, Alexandria, and Athens.

MacTutor’s Eratosthenes biography and Britannica’s life independently describe the Alexandrian librarianship as a received heading.

Established: later lives name him as librarian under Ptolemy III. Not established: an exact ISO appointment day, a surviving employment contract, or that every later Alexandrian book was his act.

Eratosthenes did not file a later UNESCO form, a later Loeb colophon, or a later museum label as a personal act.

Causal path

How this event connects to drivers and indicators in the graph.

  1. ActorEratosthenes
  2. contributed toFactEratosthenes is appointed to the Alexandrian library under Ptolemy III as later lives report
  3. strengthensDriverDigital Learning Access
  4. weakensIndicatorLearning Poverty Rate (low- and middle-income countries)

Cite this page

Factrail. (2026). Eratosthenes is appointed to the Alexandrian library under Ptolemy III as later lives report. Factrail. https://factrail.ai/facts/era-library-appointment

https://factrail.ai/facts/era-library-appointment

Accessed 16 October 2026.

By the Factrail desk · Method: how we source and score · Last reviewed

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