Lisbon Regicide
The assassination of King Carlos and the Prince Royal was the effective end of a constitutional monarchy in Portugal (later confirmed by the 5 October 1910 revolution). The regime functioned for another 33 months with growing agitation and demands for reform (although considerably less than in the future First Republic). It cannot be denied that the weak and permissive attitude in the Government of Acclamation was an incentive for the Republican Party to attempt another coup. The assassinations did not change the system of government; instead, they delayed the change.
John VI of Portugal
One of the last representatives of absolute monarchy in Europe, he lived during a turbulent period; his reign never saw a lasting peace. Throughout his period of rule, major powers, such as Spain, France and Great Britain, continually intervened in Portuguese affairs. Forced to flee to South America across the Atlantic Ocean into Brazil when troops of the Emperor Napoleon I invaded Portugal, he found himself faced there with liberal revolts; he was compelled to return to Europe amid new conflicts. His marriage was no less conflictual, as his wife, Carlota Joaquina of Spain, repeatedly conspired against her husband in favor of personal interests or those of her native Spain. He lost Brazil when his son Pedro declared independence, and his other son Miguel (later Miguel I of Portugal) led a rebellion that sought to depose him. According to recent scholarly research, his death may well have been caused by arsenic poisoning.