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Portuguese Commission for Nautical Latitude Tables

When
undated
Where
Unresolved
Episodes
1

A legacy record claims King John II of Portugal appointed mathematicians in 1484 to refine nautical latitude tables. The supplied sources confirm John II's reign and general latitude calculation methods but do not verify this specific commission, its members, or the placeholder date.

Episodes

  1. Unknown · UnresolvedUnverified Commission Appointment

    A legacy record claims John II appointed mathematicians in 1484 to refine latitude tables, but this is not supported by the provided passages.

Background and detail

Background. John II, known as the Perfect Prince, reigned as King of Portugal from 1481 to 1495. He is recognized for reinvigorating the Portuguese economy and renewing exploration of Africa and Asia. Separately, mariners calculated latitude by sighting Polaris and using sight reduction tables to correct for atmospheric refraction.

Event Status. The legacy record indicates a 1484 appointment of mathematicians to perfect latitude tables. However, the supplied passages do not contain evidence of this specific commission, its members, or its mandate. The date 1 January 1484 is a placeholder and is not confirmed by the provided sources.

People involved

Sources

  1. John II of Portugal Wikipedia, revision of 2026-07-21
  2. Navigation Wikipedia, revision of 2026-09-02

Machine-drafted from the cited Wikipedia passages and checked by a reviewing model, not by a human editor. Every passage cites the revision it was written from; dates and places follow those passages.