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
Lithuania–Poland border Lithuania–Poland border The current Lithuania–Poland border exists since the re-establishment of the independence of Lithuania on March 11, 1990. Until then the identical border was between Poland and Lithuanian SSR of the Soviet Union. The length of the border is . It runs from the Lithuania–Poland–Russia tripoint southeast to the Belarus–Lithuania–Poland tripoint. It is the only land border that the EU- and NATO-member Baltic states share with a country that is not a member of the Russian-aligned Commonwealth of Independent States. To the military planners of NATO, the border area is known as the Suwalki gap (named after the nearby