Portugal's power and wealth were greatly damaged by several successive events.

An excerpt from the article 37 facts about Portugal

It was the Lisbon earthquake in 1755, the occupation of the country during the Napoleonic Wars, the independence of Brazil in 1822, and the civil war over the royal succession. The 1910 revolution overthrew the monarchy in Portugal, establishing the democratic but unstable First Portuguese Republic, later replaced by the authoritarian Estado Novo regime.