The Santa Maria hijacking was carried out on 23 January 1961 when Portuguese and Spanish political rebels seized control of a Portuguese cruise liner, aiming to force political change in Portugal. The action was also known as Operation Dulcinea, the code name given by its chief architect and leader, Portuguese military officer, writer and politician Henrique Galvão, who had been exiled in Caracas, Venezuela since 1959. The hijacking ended when, after United States naval intervention, the ship arrived in Brazil, where the rebels were given political asylum.
Owned by the Lisbon-based Companhia Colonial de Navegação, the 609-foot-long (186 m) 20,900-ton ship was the second largest ship in the Portuguese merchant navy at the time, and along with her sister ship, Vera Cruz was among the most luxurious Portuguese-flag liners.
The ship was primarily used for colonial trade to the Portuguese overseas provinces of Angola and Mozambique, in Africa, and migrant transportation to Brazil. The ship's mid-Atlantic service was also viewed as rather out of the ordinary: Lisbon to Madeira, to Tenerife, to La Guaira, to Curaçao, to Havana (later San Juan), and lastly Port Everglades. The average trade for this gray-hulled ship was mostly migrants to Venezuela and the general passenger traffic.
On 23 January 1961, the ship had 600 passengers and 300 crew members. Among the passengers were men, women, children, and 24 Iberian leftists led by Henrique Galvão.