The castle was first constructed in the 11th century by the Moors when Arcos was briefly a taifa (small kingdom) before being captured by the Christians in 1250. The Christians rebuilt the castle as part of their campaign to retain their hold on the town, which was in a strategically important position for maintaining the border between the Muslim and Christian kingdoms. The town's suffix de la Frontera (of the frontier) was added at this time and denotes this struggle for territory. Following the Christian conquest the castle became the home of the Duke of Arcos. The castle is now privately owned and is not open to the public.