The Alcázar of Jerez de la Frontera is a group of fortified buildings of Almohad origin (probably 12th century, being the oldest Almohad building in the Iberian Peninsula), to which later Baroque palatial buildings were added, and which is one of the main monuments of the city; it is located in the southwest corner of the wall that surrounded the city, next to the Alameda Vieja.

In Muslim Jerez, the Alcazar served as a fortress-palace, the seat of power that governed the city.

It is considered to be one of the few examples of Almohad architecture in the Iberian Peninsula.

The hill on which the fortress stands (the highest elevation in the historic centre) has been inhabited since the Copper Age, in the third millennium BC.

Recently, in 2009, excavations found the remains of huts as well as traces of the presence of ancient silos that seem to correspond to prehistoric settlements, specifically from the Chalcolithic period 5,000 years ago.

Subsequently, the Tartessian, Phoenician and Roman cultures have left no architectural records in relation to the Alcazar or the fortifications of the city.

In the mid-11th century, Jerez swore allegiance to the Banu Jizrun of the Taifa kingdom of Arcos. It is precisely to this period that the first architectural remains found in the citadel belong, although they are reduced to a few foundations, made of mud-laid stones.

In the 12th century, in response to the authority of the Almoravids, Jerez proclaimed itself an independent taifa under the rule of Abul Gamar ibn Garrun, King of Ronda. From 1146 onwards it swore allegiance to the Almohads, who took control of al-Andalus in their struggle against the Christians in the north. Most of the Islamic buildings that are preserved in the Alcazar complex belong to this period, which lasted until 1248, when Jerez declared itself a vassal of the Kingdom of Castile, with Ferdinand III The Saint reigning.