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.
History of Portugal (1415–1578)
Sebastian of Portugal was the penultimate Portuguese monarch of the House of Aviz.
He was the son of John Manuel, Prince of Portugal, and his wife, Joanna of Austria. Sebastian succeeded to the throne at the age of three, on the death of King John III, his paternal grandfather. Soon after his birth, his mother Joanna of Spain left her infant son to serve as Regent of Spain for her father, Emperor Charles V. After his abdication in 1556, she served in the same capacity for her brother Philip II of Spain. Joanna remained in Spain until her death in 1573, never to see her son again. Since Sebastian was still a child, the regency was handled first by his paternal grandmother, Catherine of Austria, and then by his great-uncle, Cardinal Henry of Évora. During this period Portugal continued colonial expansion in Angola, Mozambique, and Malacca, as well as the annexation of Macau in 1557.