Carlos I (Eng. Charles), the Martyrized (Port. o Martirizado) - (Lisbon, September 28 1863 - Lisbon, February 1 1908) named Carlos Fernando Luís Maria Victor Miguel Rafael Gabriel Gonzaga Xavier Francisco de Assis José Simão of Braganza was the 33rd (or 34th according to some historians) and second last of Portugal's kings.

He was born in Lisbon, Portugal, the son of King Luís Filipe and Princess Maria Pia of Savoy daughter of Umberto I, King of Italy.

Carlos became King on October 10 1889. An intelligent but vastly extravagant man, Carlos's policies, wastefulness and extramarital affairs effectively sealed the fate of the Portuguese monarchy. Colonial treaties with the United Kingdom (one signed in August 1890 that defined their African borders along the Zambesi and Congo rivers and another signed on October 14 1899, that confirmed colonial treaties of the 17th Century) stabilised the situation in Africa. Domestically, Portugal was twice declared bankrupt - on June 14 1892, and again on May 10 1902 - causing industrial disturbances, socialist and republican antagonism and press criticism of the monarchy. Carlos responded by appointing General João Franco as military dictator.

On February 1 1908 the royal family returned from the palace of Vila Viçosa to Lisbon. They travelled by coach to Almada and from then took a boat to cross the Tagus River and disembarked in Cais do Sodré in downtown Lisbon. On their way to the royal palace, the carriage with Carlos I and his family passed through Terreiro do Paço . While crossing the square, shots were fired from the crowd by at least two men: Alfredo Costa and Manuel Buiça . The king died immediately, his heir Luís Filipe was mortally wounded, and Prince Manuel was hit in an arm. The assassins were shot at the spot by members of the bodyguard and later recognized as members of the Republican Party. About twenty minutes later, Luís Filipe also died and Manuel became the last king of Portugal.

Carlos was married to Princess Amélie of Orléans in 1886. She was daughter of Philippe, Comte de Paris and Marie Isabelle d'Orléans. Their children were

• Luis Filipe, Duke of Braganza (1887-1908)
• Manuel II, king of Portugal between 1908 and 1910 (1889-1932)
• Maria Anna of Braganza, princess of Portugal (1887).

It was alleged (many years after his death) that Carlos I had an illegitimate daughter by Maria Amelia Laredo e Murca: particulars of this claim can be found at Maria Pia of Bragança.