The European history of Fort Matanzas National Monument begins with an incident almost 200 years before the construction of the fort at Matanzas (Spanish for "slaughters") - the Spanish massacre of French forces in 1565. It took place near or possibly within the area which now makes up the monument and where this live oak tree stands. The incident initiated Spanish control of Florida for 235 years and led to the naming of the Matanzas River. Throughout its history, the story of Fort Matanzas has been closely intertwined with that of the city of St. Augustine and the Castillo de San Marcos .