Battles & Campaigns · 1777
First Treaty of San Ildefonso
Royal Palace of La Granja de San Ildefonso, Segovia, Spain
What happened
Spain and Portugal had argued for almost 300 years over where their South American lands met, and fought a short war in 1776–1777. When Portugal's King Joseph I died, the new queen, Maria I, sought peace. Spain kept Colonia del Sacramento, and Portugal kept southern Brazil and got the island of Santa Catarina back.
Why it matters
It settled a very long border dispute around the Río de la Plata. A commission was set up to mark the borders on the ground.
What came next
The Treaty of El Pardo confirmed the borders in 1778. In 1801 the Treaty of Badajoz gave the Misiones Orientales back to Portugal.
Did you know?
The Misiones Orientales were Jesuit missions to the Guaraní people, which inspired the 1986 film 'The Mission'.
Timeline
- Feb 1776Spanish–Portuguese War begins.
- 24 Feb 1777King Joseph I of Portugal dies.
- 1 Oct 1777First Treaty of San Ildefonso.
- 11 Mar 1778Treaty of El Pardo.