This 1778 treaty resolved Iberian territorial disputes in South America and Africa, reshaping colonial boundaries that define modern Uruguay, Brazil, and Equatorial Guinea.
Key Facts
- Date signed
- 11 March 1778
- Colonia del Sacramento
- Confirmed as Spanish possession (now Uruguay)
- African territories ceded
- Portugal ceded lands now comprising Equatorial Guinea
- Spanish withdrawal
- Spain relinquished lands in modern Rio Grande do Sul, Brazil
- Primary dispute region
- Río de la Plata (modern Argentina–Uruguay border area)
Location
Cause → Event → Consequence
Spain and Portugal had long competed for dominance in the Río de la Plata region, particularly over the strategically valuable settlement of Colonia del Sacramento. Overlapping colonial claims in South America and Africa created persistent friction between the two Iberian powers throughout the eighteenth century.
On 11 March 1778, Spain and Portugal signed the Treaty of El Pardo to resolve their colonial disputes. Spain secured formal recognition of its ownership of Colonia del Sacramento, while Portugal transferred strategically important African territories—corresponding to present-day Equatorial Guinea—to Spanish control in exchange for Spanish concessions.
The treaty redrew Iberian colonial boundaries in both South America and Africa. Spain consolidated its hold over the Río de la Plata zone, while Portugal retained influence over lands now in southern Brazil. The African territories ceded by Portugal eventually became the modern state of Equatorial Guinea, Spain's only sub-Saharan African colony.
Political Outcome
Spain gained confirmed ownership of Colonia del Sacramento and African territories now comprising Equatorial Guinea; Portugal retained lands in modern Rio Grande do Sul, Brazil.
Disputed colonial claims over Colonia del Sacramento and territories in the Río de la Plata region and Africa between Spain and Portugal.
Spain held Colonia del Sacramento and African territories (future Equatorial Guinea); Portugal secured its claims in southern Brazil.