**1. Introduction**

Islamic ceramic manufacture in northern al-Andalus (the Muslim part of the Iberian Peninsula) is less known; however, the study of production centers from some small, but splendorous, kingdoms in the Peninsula can improve general knowledge and add new insights into medieval ceramic technology. The Iberian Peninsula was part of the Islamic culture since the 8th century CE, but it was in the 10th century CE when it reached its political independence from the Damascus caliphate. At the beginning of the 11th century CE, al-Andalus was divided in small kingdoms (called *Taifas*), such as Toledo, Cordoba, Granada, or Zaragoza (Figure 1). This was the case of Albarracin *Taifa*. Nowadays, Albarracin is a town located in the NE of the Iberian Peninsula, in a mountain range in the current Aragon. Its good situation in an environment with lots of natural resources (water, vegetation and animals) has favored human habitation since ancient periods, as is shown by the rock art found in the surroundings that dates from the 6th millennium BCE [1]. Albarracin *Taifa* was governed by a Berber family, the Banu-Razin, and it had a flourishing cultural and economic development which reflected the influence of the Muslim society in different aspects of its way of life and also in ceramic production [2,3]. At the beginning of the 12th century CE, the kingdom was under the influence of the Almoravid

**Citation:** Pérez-Arantegui, J.; Marzo, P. Characterization of Islamic Ceramic Production Techniques in Northeast Iberian Peninsula: The Case of Medieval Albarracin (Spain). *Appl. Sci.* **2021**, *11*, 7212. https:// doi.org/10.3390/app11167212

Academic Editors: Marco Martini, Anna Galli and Asterios Bakolas

Received: 30 June 2021 Accepted: 3 August 2021 Published: 5 August 2021

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political power from Valencia and Murcia. At the end of the 12th century CE, in 1170, Albarracin was given to the Christian Azagra family, but at the same time it preserved its independence from Aragon and Castile during two centuries; this allowed it to continue economic relations not only with northern Iberian regions dominated by Christians but also with Muslim kingdoms [2,3]. All these features reveal a great interest on the study of ceramic productions in Albarracin *Taifa* in order to understand pottery characteristics, technology and actual exchanges between different workshops in the 11–12th centuries CE. Moreover, this area could be the origin and the connection with later important glazed ceramic manufacture centers, such as workshops from Teruel and Valencia.

**Figure 1.** Map of the Iberian Peninsula, showing the approximate border between Islamic and Christian areas at the beginning of the 11th century CE, with some of the main centers of ceramic production.

During the Islamic period, ceramics was one of the most important industries in the Iberian Peninsula due to great trade development, with the production, exportation and importation of ceramic objects. Pottery reflected the influence of Muslim culture, not only in decorative styles but also in decoration technology. As well as a continuity of the production of lead glazes developed in earlier periods, some new technologies were widespread in the *Taifa* kingdoms. The addition of tin oxide to the glazes to obtain opaque decorations was imported from the Middle East and northern Africa in the 10th century CE, or at the end of the 9th century CE. Initially, tin-opacified glazes decorated with green and brown designs on white surfaces were produced in the caliphal Cordoba [4], but the style was fast spread to all the other later kingdoms [4,5]. Another kind of decoration introduced in this period by Muslims was *cuerda seca*. This technique was an important style in al-Andalus, confirmed by the different productions found around the Iberian Peninsula [6,7]; it is characterized by a black line that delimits the drawing of the decoration, and the spaces between lines were filled totally or partly with colored glazes. The geometric and vegetable motifs were common in the techniques of both white tin-opacified glazes and *cuerda seca*.

The continuous Islamic influence in the ceramic production of the Iberian Peninsula was not only present in decoration technology, such as the introduction of tin-opacified glazes and the *cuerda-seca* technique, but also in the decorative styles. All these characteristics and techniques were applied in ceramic production from Albarracin *Taifa* dating from the 11–12th centuries CE, as the numerous objects found during several archaeological excavations have proved. This production was the subject of our study. The research was focused on the technology of production and decoration of the diverse ceramics found in Albarracin from the *Taifa* period.

The aim of this work was the characterization of the Islamic ceramic production of Albarracin in order to establish ceramic reference groups of this period in the *Taifa* and determinate the possible influences of the pottery manufactured in other Islamic kingdoms. To carry out these objectives, the study was focused on the chemical composition of the materials employed in the clay bodies, and on aspects of the decoration related to the composition of the materials and their contribution to the glaze characteristics and to the manufacture process. Finally, this study intended to establish relations between the variations of the raw materials depending on the type of decoration and compare the compositions used in their manufacture with other workshops of the same period.
