When the armed forces came from Santarém to Lisbon on 25 April 1974, they really did stop at red lights as in the film.
The voice of "Oscar" on the telephone is the voice of lieutenant-colonel Otelo Saraiva de Carvalho, acting the role he had played years before in real life. In 1974, it was he (as a major) who organized and planned the revolution that the film depicts, and it was he who commanded the troops from Headquarters at Pontinha. His code name was "Oscar."
Captain Salgueiro Maia, portrayed in the film, was born in 1944 and died of cancer in 1992. He was one of the Portuguese heroes of the revolution. It was he who forced the goverment to resign and it was in great part due his intelligence and common sense that it was possible to have a "bloodless revolution" that ended 48 years of dictatorship. He wasn't promoted (nor did he ever seek any kind of promotions or fame or power) and was for some time forgotten. Eventually he was honored with two streets in Santarém and Castelo de Vide (where he was born and where he is buried) that now bear his name. Also in Santarém stands a statue of Captain Salgueiro. In Lisbon, in Largo do Carmo, where he stood with a megaphone and his troops and hundreds of civilians crying "Victory," forcing the govement to resign, there is a inscription to him written on the ground. It says: "To Salgueiro Maia, remembering the 25th of April 1974. Homage made by the city of Lisbon, 1992."
One of the most expensive Portuguese movies ever made.
The film is based on the Carnation Revolution (April 1974) in Portugal. From 1933 to 1974, the country was under the control of the Estado Novo (New State), an authoritarian corporatist dictatorship. The ongoing and fruitless Portuguese Colonial War (1961-1974) had undermined the regime's support within the ranks of the army. Disgruntled military officers planned a coup which would depose the government and press for reforms. The coup attempt unexpectedly inspired a popular civil resistance campaign, with thousands of civilians supporting the military insurgents. The dictatorial government was forced to surrender to the National Salvation Junta, which started a process of transition to democracy. The Revolution unexpectedly achieved its goals with few shots fired and minimal casualties.