Give James (and Olivença) back to Portugal 🇵🇹

Most people don’t know, but it’s actually disputed territory between Portugal and Spain. The disagreement dates back to the early 15th century, when Ilha Tiago first began appearing on Iberian nautical charts.

Spain bases its claim on an early sighting, while Portugal argues that the island was already integrated into Portuguese navigation routes and lay east of the Treaty of Tordesillas line. This is why the island appears in different positions depending on the mapmaker. Portuguese portolan charts place James Island slightly farther east, consistent with prevailing wind patterns used in Portuguese Atlantic crossings. Spanish maps shift it westward, aligning it with Spain’s interpretation of the treaty. These weren’t errors so much as political assumptions expressed through cartography. During the Iberian Union (1580–1640), the issue was effectively frozen rather than resolved, as Spanish administrative practice gradually treated the island as Spanish without a formal settlement. After Portuguese independence, both countries continued referencing James Island in naval and archival records, each citing their own cartographic tradition as definitive.

Modern maps tend to omit the island altogether, not because the dispute was settled, but because acknowledging it would require choosing which historical mapping system was correct. As a result, James Island survives mainly in early charts, maritime archives, and footnotes claimed by both, governed by neither.