Castles in Spain. History.

General Introduction.
There are thousands of castles scattered throughout Europe. Like churches and monasteries, they were part of everyday life in Medieval Europe.  While churches and monasteries spoke of ecclesiastical power, the castles signalled military –and by extension political– strength. (In al-Andalus –as Muslims called the area of Iberia they occupied– mosques played a similar role to churches.)

The great Moorish castle of Gormaz, with the village of Gormaz gathered below it.

A number of factors determined a castle’s shape and size: geographical features, availability of water, political needs, manpower required and available, and the nature of the materials that could be used.

Castles can be found crowning high crags, controlling the approach to fertile valleys, guarding strategic passes or travel routes, looming up across the distance of a plain and protecting estuaries and coastal areas. Those on top of hills used the high ground as part of their defence, those on plains were protected by deep and wide moats, often filled with water. (Google Medieval Castle Designs for an idea of the enormous variety of castle plans.)

Castles served primarily to protect people and territory. Their function could be defensive (against enemy forces), or offensive (built by invading armies to consolidate gains and signal their intention to remain in the newly conquered lands).

Castles were constructed at the command of rulers to keep their lands under surveillance, but the lack of centralised power especially during the early Middle Ages also encouraged the proliferation of castle building by ambitious or rebellious lords and princes. In these cases, they also became symbols of success, status and personal prowess.

Together with religious institutions, castles exerted enormous influence on life in Europe between the 10th and 15th centuries. We tend to think of castles simply in military terms, but they also helped to shape the social, economic and cultural life of people during this period.

Villages and towns frequently established themselves around castles, creating hubs that provided work for the inhabitants. In times of hostility, those inhabitants could seek protection inside the castles. In return for protection, villagers often surrendered their freedom and became vassals of the lord of the castle, creating one of the most identifiable social structures associated with this period: feudalism (in general terms, a contract whereby a king or lord allowed a vassal to use his land in return for homage and service whenever called upon).

However, in Spain, and more specifically in the medieval kingdoms of Castile, León, Navarre and Aragón, the feudal system never took firm root because of the need to encourage citizens to populate or repopulate lands on the borders with Muslim al-Andalus.  

Castles were built and existing towns strengthened as centres of resistance to the threat of Muslim expansionism.  In return, monarchs or nobles offered willing citizens certain inducements/privileges (e.g. ownership of land, freedom from taxation, keeping the profits of war) for settling and defending frontier zones.   

These privileges –legally recorded and known as fueros or charters— differed from area to area, but in general they outlined both the obligations and freedoms of the settlers and protected them from servitude.

Castles in Spain.
The impact and early significance of castles in Spain can be measured by the fact that the noun “castle” (from the Latin castella meaning “castles”) forms the origin of the name of Spain’s historically most powerful kingdom: Castile. And the history of Castile –the land of castles– projects itself widely over the history of Spain, and its language —el castellano— has become a synonym for Spanish, now one of the most
widely spoken languages in the world.

Map of Iberia ca. 900

As early as 800, an area running between the upper Ebro and the upper Duero rivers was already known as Castella.  For the name Castella to take root in that area there must have been sufficient fortifications dotting the landscape. 

In these early years, their presence would have responded to the advances of the Moors (Muslim forces) who had entered Hispania (as the Iberian Peninsula was called then) near Gibraltar in 711 and swept swiftly northwards. By 720 they had taken virtually all the peninsula and established a major garrison in Zaragoza on the Ebro River, and others in an arc running roughly down through Medinaceli, Trujillo and Coria.

Although Christians and Moors continued to build castles to protect their lands and advance their territories from the 8th to the 15th centuries, there are some important historical factors to keep in mind:

1. It should not be assumed that the division between Moors and Christians was absolute or that there was unanimity and harmony within each group. Frontiers regularly fluctuated within Christian and Moorish kingdoms and between  Christian Spain and al-Andalus. 

As a result, castles on all sides were regularly besieged, changed hands and were often modified to meet the needs of the conquerors or to face the challenge of new siege techniques.

Several Christian kingdoms arose during the early Middle Ages, including León, Navarre, Aragón, Castile, and the “County” (Condado) of Barcelona (although not officially a kingdom, the County of Barcelona was to all intents a self-governing entity in its early days). These kingdoms were often hostile rivals and regularly sought the help of Muslim rulers.

There were internal conflicts, too, within al-Andalus, which culminated with its disintegration into several taifas (small kingdoms) in the 11th century. The taifas, like their Christian counterparts, were often at odds with each other and sought the help of Christian soldiers

2. Castles were not built only in response to hostility between Christians and Moors but also by Christian and Moorish rulers to control internal conflicts. They were also constructed by ambitious and rebellious nobles on both sides, especially in those areas far removed from immediate royal authority.

3. We should keep in mind that large numbers of castles, both Christian and Muslim, are now in ruins and in many cases their earliest structures are hardly visible. Others have been renovated to become boutique hotels or paradores , i.e. state run hotels, e.g. Oropesa, Carmona, Jaén.

They were built, often on sites previously occupied by Roman, Visigothic, even Celtiberian fortresses, and then rebuilt or modified according to military need or the demands of a particular owner, so that in many instances what we see now are later alterations or additions.

Castles and Geography.
There are castles all over the Iberian Peninsula (Spain and Portugal), but castles built by the Moors are notably absent from the north west of the peninsula.  One way of determining the maximum extent of al-Andalus in Spain (i.e. the height of Moorish dominance, from the 8th to the 10th centuries) is by the names of numerous towns derived from various Arabic names for castles, fortifications, forts etc.

We find these almost exclusively in Andalusia, Extremadura, Castile-La Mancha, the eastern half of Castile-León, Murcia, Valencia and up to Aragón, i.e. those areas settled by the Moors. So, for example, from the Arabic al-qasr (the fortress/ castle or fortified palace) we get Alcázar: Alcázar del Rey, Alcázar de San Juan (both in Castile-La Mancha), Alquézar (Aragón).

From the Arabic al-qal’a (“the citadel”) comes Alcalá, e.g. Alcalá de Guadaira and Alcalá la Real (both in Andalusia), Alcalá de Henares (Community of Madrid), Alcalá de Ebro (Aragón). In addition, dropping the Arabic definite article “al” (“the”) results in Calatayud (Aragón), Calatrava (Castile-La Mancha), Calatañazor (Castile-León), Calasparra (Murcia).

The Arabic hisn (“stronghold”) gives us Iznalloz, Iznate, Iznájar, Aznalcóllar, Aznalcázar (all Andalusia).

Al-qasbah (i.e. a citadel or walled-fortification that commands a city) provides us with alcazaba. While there are two small villages with that name, there are plenty of examples of alcazabas located in larger cities, e.g. Almería, Alicante, Antequera, Badajoz, Málaga, Granada, Zaragoza.

Nevertheless, the presence of a Moorish castle was not always signalled by the above prefixes, and hundreds of Moorish castles can be found in places without any “castle” identifier: e.g. Badajoz, Trujillo, Gormaz (one of the most famous of all Moorish castles. See photo above), Baños de la Encina etc. etc.

Some structural characteristics of Moorish castles: 
Although not absolute, there are some general structural differences between Christian and Moorish castles. The key word is “general” because castle construction did not obey hard and fast rules, such as those that clearly distinguished churches and mosques (e.g. the cruciform or basilical shape of the church with the altar usually facing Jerusalem, or the remarkable width of numerous mosques to accommodate as many people as possible in the first row since the first row was closest to the qibla, the wall that directed the faithful towards Mecca).

In addition, mutual influences inevitably occurred with the proximity of both parties, e.g. tall keeps –a feature of Christian castles—were gradually adopted by the Moors, and albarrana towers –a characteristic of Moorish castles—were embraced by Christians.

1.  Although the Moors used both rough stone and ashlar (cut, squared, finished stone), the preferred method, especially in the south, was tapial, or “rammed earth/clay” walls.

Tapial or Formwork.

This was done by aligning a series of parallel wooden planks one above the other to a manageable height. The planks were kept separate by horizontal struts and prevented from collapsing by vertical wooden supports on the outside.

The result was an elongated box (known as “formwork”) into which a mixture of earth, gravel, lime and sometimes limestone was poured from above and then rammed solid (nowadays, cement is frequently set in this way). After the mixture had hardened, the wooden box was removed and moved up to increase the height or sideways to increase the length.

Traces of the horizontal planks and holes created where the exterior supports were joined to the planks can still be seen in numerous Islamic castles. Excellent examples are the 10th-century castle of Baños de la Encina (aka Burgalimar castle) or the 13th-century Alcalá de Guadaira.

Banos de la Encina. Tapial walls.
Alcala de Guadaira. Tapial walls.

2. From an early date, the main defensive wall or enceinte of Muslim castles usually had square or rectangular towers and battlements. Similar walls of Christian fortresses were more likely to have semi-circular towers.

Three fine examples of Moorish castles are Trujillo, Gormaz, and Baños de la Encina. A good instance of the round-towered Christian castle is the late 12th-century Castillo de Haro, evocatively located in solitary splendour on a hilltop about 70 kilometres south west of Cuenca. It was built to defend land newly conquered from the Moors.

Trujillo castle with square towers.
Haro castle with round towers.

The alcazaba of Almería offers an example of both Moorish and Christian preferences in castle construction. The alcazaba (10th century and later enlarged) has rectangular towers.  When the citadel fell to the Catholic Monarchs, Ferdinand and Isabel, in 1488, they added round towers and a keep to its western end.

Almería castle. Moorish square towers, with square keep (back middle) and round tower (back left) added by Catholic Monarchs.

Nevertheless, despite the military advantage of the round tower –better to deflect stones and arrows– the square towers still prevailed in Moorish castles into the 13th, even 14th, century when al-Andalus had been reduced to the kingdom of Granada.

Two notable examples are the 13th-century Almohad castle of Alcalá de Guadaira with its nine square and two polygonal towers, and the imposing  Alhambra towering over Granada.

Alcalá de Guadaira.
Alhambra from Plaza San Nicolás.

The 14th-century castle of Antequera:

Antequera. Alcazaba walls.

3. Horseshoe arch entrance.

Trujillo castle entrance. Triple horseshoe archway and ramp.

It is present in the earliest castles, e.g. Calatayud (8-9th century), Alora (9th century), Trujillo, Gormaz, and survives into the 14th century in the magnificent double horseshoe that forms the Gate of Justice, the main entrance of the Alhambra fortress. The old walls of Toledo also have excellent examples of horseshoe arches, e.g. the 9th century Puerta de Alfonso VI (aka the Old Puerta de Bisagra) or the Puerta de Alcántara.

4.  Torres albarranas. These were towers detached from the curtain walls and linked at the top to the walls by a protected bridge or walkway. They are commonly associated with Almohad structures (12th- 13th centuries) and are numerous throughout the southern half of the peninsula.

These towers made excellent platforms for defenders to protect the walls from a wide angle, allowing bowmen, for example, to shoot at attackers who had reached the base of the curtain walls without having to expose themselves too much.

Although the torres albarranas were initially rectangular in shape (e.g. Trujillo has two) those built by the Almohads (12th-13th centuries) tended to be polygonal, all the better to deflect missiles than the rectangular towers.

Trujillo castle. Albarran tower upper right.
Seville’s Torre del Oro.

Among the most notable examples are the late 12th-century octagonal Torre Espantaperros in Badajoz, the Torre Mochada in Caceres, and the most famous of all, the remarkable 12-sided Torre del Oro (Golden Tower, above) in Seville, not far from the Cathedral.  Built in 1220, the Torre del Oro now stands alone on the bank of the Guadalquivir, the wall to which it was originally attached –running from the Alcazar further inland– having been long dismantled.

5.  The Almohads are also commonly credited with introducing the elbow entrance into al-Andalus.

Toledo. Puerta de Alcantara. The second bend is to the left, framed inside the main horse- shoe arch.

The simple introduction of a bend became an effective means of obstructing direct and speedy entry and made it much easier for defenders to cut down attackers.

A good example is the Puerta de Alcántara (Alcántara Gate) in Toledo; it was rebuilt by Henry iv in the 15th century, but retained its Moorish design). The Gate of Justice entrance to the Alhambra Palace of Granada has in fact a triple bend, something that all visitors to the complex have to pass through if they chose to approach the Alhambra from the Plaza Nueva and up the Cuesta de Gomérez (nowadays, the main entrance is near the Generalife gardens, and the easiest way to get there is by bus or taxi).

6. Freestanding watchtowers —atalayas— are quite common throughout Spain and were widely used by the Moors and Christians. These were normally located on a high frontier point which usually formed part of a network of other atalayas and castles, each within sight of the other.

Atalaya within sight of Gormaz castle.

They were manned by a few soldiers, but their main function was to keep an eye on frontier activities which could be rapidly communicated to the nearest castle.


Interesting as they are, the structural features of castles are only part of a much larger picture of Medieval life in Christian Spain and al-Andalus. Life in castles varied according to their principal function, location and size. But that is another story …..

Barracund, Marianne and Bednorz, Achim  Moorish Architecture in Andalusia Cologne 1992

Glick, Thomas    From Muslim Fortress to Christian Castle Manchester 1995 
Gallacher, Stuart “Castles in Spain,” in The Journal of American Folklore 76, No. 302 (Oct-Dec, 1963), 324-329.
Kaufmann, J.E & H.W    The Medieval Fortress  Cambridge, MA 2004
 Manchester 1995 
Gallacher, Stuart “Castles in Spain,” in The Journal of American Folklore 76, No. 302 (Oct-Dec, 1963), 324-329.
Kaufmann, J.E & H.W    The Medieval Fortress  Cambridge, MA 2004
Michel, George ed.  Architecture of the Islamic World: Its History and Social Meaning New York 1978 
Peter A Burton “Islamic Castles in Iberia” in  in The Castle Studies Group Journal No 22: 2008-

9, pp. 228-44. 
Tapial image: “Tapialdebarro” by Nubarron – Own work. Licensed under GFDL via Commons –
Alcalá de Guadaira: “Fortaleza mozárabe Alcalá de Guadaíra” by Rafax – Own work. Licensed under Public Domain via Commons –
Baños de la Encina by Wikibrense:
“Alcazaba de Almería” by ANE – Own work. Licensed under CC BY 3.0 via Commons – 
Alcalá de Guadaira Castle « Castillo de Alcalá de Guadaíra. Vista desde el barrio del arrabal o barrio del castillo » par Juan Luis Jiménez Lillo — Travail personnel. Sous licence CC BY-SA 3.0 es via Wikimedia Commons –
Puerta de Alc
ántara “Puerta de Alcántara, Toledo” by Jose Luis Filpo Cabana – Own work. Licensed under CC BY 3.0 via Wikimedia Commons –,_Toledo.jpg#/media/File:Puerta_de_Alc%C3%A1ntara,_Toledo.jpg
The following article was located following the writing of the above post. It is not a source, but is added for anyone interested in the topic: