History of Portugal (1640–1777) put to the test in 1762 when Spain invaded aided by France, during the Seven Years' War. Britain invoked its alliance with Portugal and sent troops. Several months later, the conflict was settled with comparatively little fighting. In 1777, Spain and Portugal signed the Treaty of San Ildefonso, which mainly resolved a number of border disputes between their South American colonies. During the Age of Enlightenment, Portugal was considered one of Europe's unenlightened backwaters; it was a country of three million with 200,000 people in 538 monasteries in 1750. Melo seems to have been deeply embarrassed by Portugal's much lamented
São Pedro do Sul, Portugal the 6th century BC, lacking streets of right angles and full of construction almost always circular. One of the Castros in São Pedro do Sul is Castro da Cárcoda. In the region exist several Roman bridges and Roman Thermal Spas. São Pedro do Sul was the southern border of the Kingdom of Portugal at the time of the Foundation of the country, being the natural border the river Vouga that's the reason of the name "Saint Peter of South". The first King of Portugal Afonso Henriques lived in São Pedro do Sul while healing is injuries after the battle of