the prince of Portugalin 1522 choose to liberate Brazil from Portugal then went to invade Portugal later and became king before dying from TB... damn i aint know all that
What happened to Portugal? It was a world power with a naval presence, great explorers, and colonies around the world in the 1400s/1500s, but doesn't have the same stature now. - Quora
There are many dates that show the downfall of Portugal from grace. The main ones, in my opinion:
- 1580 - following the disappearance of the king in battle, Spain invades and claims the Portuguese throne, beginning the Iberian union that lasted until 1640.
- 1755 - as the Brazilian gold is starting to run out, a huge earthquake hits Lisbon - you can’t make this stuff up - the rich Imperial capital crashes down and burns, killing thousands and starting a huge crisis. The municipality of Ouro Preto where gold was found was the most populous city of Latin America, counting on about 40 thousand people in 1730 and, decades after, 80 thousand. At that time, the population of New York was less than half of that number of inhabitants and the population of São Paulo did not surpass 8 thousand
- 1806 - Napoleonic wars, the entire royal court flees to Brasil, moving the Capital to Rio de Janeiro. The duke of Wellington comes to help repel the French, the war leaves Portugal devastated.
- 1810–1910 - Portugal loses Brasil in 1822, is left economically devastated, declares bankruptcy multiple times, faces civil war and multiple rebellions.
- 1910 - Republican revolution. the 1st republic lasts 16 years and has 45 different governments
- 1916 - Portugal joins WW1, in a effort to keep its colonies, it works
- 1926 - after a period of political assassinations and ungovernability, a new military-backed dictatorship begins.
- 1961 - Beginning of African Colonial wars
- 1974 - End of the dictatorship, Portugal formally (and chaotically) abandons all of its colonies at the same time (except Macau). The country starts becoming what it is today.
The loss of independence in 1580 is relevant as it is a clear date when Portugal stopped being able to defend its colonies and started losing territory instead of expanding. Spain neglected the Portuguese colonies and used (read: lost) the Portuguese navy in its European wars. After the independence is re-established in 1640, many colonies are recovered, but the country largely missed out on the golden age of early settling and establishing trade posts and never becomes expansionist again.
The key aspect though, is in the highlighted 1755. The Lisbon earthquake hits Lisbon right at the start of the industrial revolution, and Portugal misses out largely on this period, never really catching up with the rest of Europe.
During the XIX century, when France and Great Britain reached the peak of colonial expansion, Portugal was simply bankrupt. Without an industry and facing constant instability, Portugal managed no more than to keep its colonies, largely due to the diplomatic will of GB.
Finally, in the XX century, Portugal is stuck in a corner of Europe, poor and under developed, and managing a vast colonial empire that cannot really afford. The regime was super traditionalist and industrialisation was not a priority. It closes itself to the outside world and tries to keep its colonies at all costs, but could’t really pay for those costs and the economy in Portugal starts to deteriorate even more, while the rest of Europe was booming.
After the 1974 revolution the decision to drop all the colonies at once was not surprising. People just wanted the war to end and nobody could be fooled into believing they were “ours” anymore.
So this is story of how Portugal became this:
Do you even realize how much the US fell of to the rest of the world, especially the last few years? 
