Lisbon Regicide: King Carlos I of Portugal and Infante Luis Filipe are shot dead in Lisbon.

The Lisbon Regicide or Regicide of 1908 was the assassination of King Carlos I of Portugal and the Algarves and his heir-apparent, Luís Filipe, Prince Royal of Portugal, by assassins sympathetic to Republican interests and aided by elements within the Portuguese Carbonária, disenchanted politicians and anti-monarchists. The events occurred on 1 February 1908 at the Square of Commerce along the banks of the Tagus River in Lisbon, commonly referred to by its antiquated name Terreiro do Paço.

Dom Carlos I, known as "the Diplomat", "the Oceanographer" among many other names, was King of Portugal from 1889 until his assassination in 1908. He was the first Portuguese king to die a violent death since King Sebastian in 1578, the only one to be assassinated, and the second to last Portuguese head of state to die a violent death.

Dom Luís Filipe, Prince Royal of Portugal, Duke of Braganza was the eldest son and heir-apparent of King Carlos I of Portugal until his assassination. Born in 1887, when his father was still Prince Royal, he was styled Prince of Beira at birth. After his grandfather King Luís I of Portugal died, he became Prince Royal of Portugal and Duke of Braganza as heir apparent to the throne. Following the Lisbon Regicide, that saw him and his father killed, his youngest brother Manuel II became King of Portugal.

Lisbon is the capital and largest city of Portugal, with an estimated population of 575,739, as of 2024, within its administrative limits and 3,028,000 within the metropolis, as of 2025. Lisbon is mainland Europe's westernmost capital city, and the only one along the Atlantic coast, the others being on islands. The city lies in the western portion of the Iberian Peninsula, on the northern shore of the River Tagus. The western portion of its metro area, the Portuguese Riviera, hosts the westernmost point of Continental Europe, culminating at Cabo da Roca.