## 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 8 th century CE, but it was in the 10 th century CE when it reached its political independence from the Damascus caliphate. At the beginning of the 11 th 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 6 th millennium BCE [1]. Albarracin _Taifa_ was governed by a Berber family, the [PERSON], 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 12 th century CE, the kingdom was under the influence of the Almoravid political power from Valencia and Murcia. At the end of the 12 th century CE, in 1170, Albarracin was given to the Christian [PERSON] 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 11-12 th 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. 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 10 th century CE, or at the end of the 9 th 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 11-12 th centuries CE, as the numerous objects found during several archaeological excavations have proved. This production was the subject of our study.