Brazil–Colombia border
A long Amazon border set in two steps: a 1907 treaty along the Amazon–Orinoco watershed and a string of rivers, and a 1928 treaty that simply took over an old Brazil–Peru line once Colombia gained the Leticia trapezium.
Written from cited sourcesLast checked 29 September 2026Suggest a correction
See it on the globe:Brazil →Colombia →
Spain, Portugal and the Amazon
The Treaty of Tordesillas of 1494 gave Spain most of the Amazon basin on paper, but Portuguese explorers pushed far up the river from its mouth. The Treaty of Madrid of 1750 recognised that, drawing a line far inland to the westernmost mouth of the Caquetá, though surveyors quarrelled and fought their way through the forest and the work was suspended in 1761. Spain and Portugal tried again at San Ildefonso in 1777.[1]
After independence, a Brazil–Colombia treaty of 24 April 1907 set the northern part of the line: from the Rio Negro north-west along the Amazon–Orinoco watershed, then south along rivers and straight lines to the mouth of the Apaporis. It was the first successful Brazilian–Colombian boundary agreement.[1]
Inheriting a line
The land between the Apaporis and the Amazon was disputed between Colombia and Peru. In a 1922 agreement Peru gave up its claims there, giving Colombia the Leticia area on the Amazon; after Peruvian irregulars occupied Leticia a decade later, the League of Nations restored the 1922 terms in 1934.[1]
That swap wiped out part of an established Brazil–Peru border, so a treaty signed in Rio de Janeiro in 1928 made the old Brazil–Peru geodesic line from Tabatinga to the mouth of the Apaporis the Brazil–Colombia border. In 1985 a dirt road from Tabatinga gave Brazil its ground link to Leticia.[1]
Timeline
1494
Tordesillas
Spain and Portugal divide the world by a line in the Atlantic.[1]
1750
Treaty of Madrid
A line far inland recognises Portuguese settlement.[1]
190724 April 1907
Brazil–Colombia treaty
The northern part of the border is set.[1]
1922
Colombia–Peru accord
Peru gives up the Apaporis–Amazon area.[1]
1928
Rio de Janeiro treaty
The old Brazil–Peru line becomes the Brazil–Colombia border.[1]
More borders
Sources
- [1]International Boundary Study No. 174: Brazil – Colombia Boundary · US Department of State, Office of the Geographer · 15 April 1985
Map geometry from Natural Earth via world-atlas. See credits.