The date of 1st December 1640 represents an important milestone in the History of Portugal: the demise of the "Sixty Years of Captivity" under Spanish ruling.
Following the death of the young Portuguese King Sebastićo at Al Kasr al Kebir, Philip II of Spain had claimed the throne of Portugal and had been crowned king as Philip I of Portugal in 1581. For sixty years - known as the "Sixty Years of Captivity" - Portugal was ruled by Spanish kings as a separate kingdom. On December 1st, 1640, with the help of the people and the nobility, Joćo, 8th Duke of Braganza, took various strategic points and formed a provisional government under the archbishop of Lisbon.
Joćo IV is proclaimed king of Portugal
The Duke of Braganza was crowned as Joćo IV on December 13, therefore putting an end to the "Sixty Years of Captivity", and the throne passed to the house of Braganza.