1494 AD
Tordesillas draws an imperial line across the ocean
Oceans, navigation & cartography · Nautical cartography · Empire, trade & power
Castile and Portugal agreed on a pole-to-pole demarcation line 370 leagues west of Cape Verde to divide spheres of expansion. Without a reliable way to determine longitude at sea or consent from affected peoples, a cartographic and legal abstraction claimed authority over territories and oceans unknown to both crowns.
Precision, calendar, and review
- Start
- year · no uncertainty qualifier in this record
- Calendar and convention
- Historical-era years; the source calendar is not identified. No conversion of days is assumed.
- Year zero
- The scale goes from 1 BCE to 1 CE without year zero. Changing era names changes labels only.
- Documentary review
- Date not recorded
Reading the date: point event.
Sources
- www.unesco.org (opens in a new tab)
Source provenance and scope
- Publication date
- 2026-04-29
- What this date describes
- The cited source or edition; it may postdate the historical event.
- Source updated
- 2026-04-29
- Bibliographic date checked
- 2026-09-23
- Date evidence
- Declared in the cited source’s publisher metadata.
The correspondence between this reference and individual claims has not yet been itemized.
This record is an editorial synthesis. Consult the sources to check claims and their limits. Chronological relationships alone do not establish causation.