Martyrs' Day is observed in São Tomé and Príncipe every February 3 to commemorate the soldiers who lost their lives in the struggle for independence from Portugal. The islands were discovered by Portuguese sailors in the 15th century and became part of the Portuguese colonial empire in the 16th century. The unrest among plantation workers, who faced forced labor and poor working conditions, escalated in the 20th century, culminating in the Batepá Massacre in 1953, where several hundred African laborers were killed. In the late 1950s, São Toméans formed the Movement for the Liberation of São Tomé and Príncipe, leading to the overthrow of the Caetano dictatorship in 1974 and the country's independence on July 12, 1975. On Martyrs' Day, the nation pays tribute to all who died in the fight for independence, reflecting on the historical significance of their sacrifices.