(and which had been turned into mosque lamps) back to Santiago de Compostela. Despite the conversion, the early Christian history of the building saw only minor alterations being done to its structure, mostly limited to the creation of small chapels and the addition of new Christian tombs and furnishings. Even the mosque's minbar was apparently preserved in its original storage chamber, though it is unknown if it was used in any way during this time. (The minbar has since disappeared, but it still existed in the 16th century, when it was apparently seen by Ambrosio de Morales.) The cathedral's first altar was installed in 1236 under the large ribbed dome at the edge of Al-Hakam II's 10th-century extension of the mosque, becoming part of what is today called the Villaviciosa Chapel (Capilla de Villaviciosa) and the cathedral's first main chapel (the Antigua Capilla Mayor). There is no indication that even this space was significantly modified in its structure at this time. The area of the mosque's mihrab and maqsura, along the south wall, was converted into the Chapel of San Pedro and was reportedly where the host was stored. What is today the 17th-century Chapel of the Conception (Capilla de Nuestra Señora de la Concepción), located on the west wall near the courtyard, was initially the baptistery in the 13th century. These three areas appear to have been the most important focal points of Christian activity in the early cathedral. The minaret of the mosque was also converted directly into a bell tower for the cathedral, with only cosmetic alterations such as the placement of a cross at its summit. Notably, during the early period of the cathedral-mosque, the workers charged with maintaining the building (which had suffered from disrepair in previous years) were local Muslims (Mudéjars). Some of them were kept on payroll by the church but many of them worked as part of their fulfilment of a "labor tax" on Muslim craftsmen (later extended to Muslims of all professions) which required them to work two days a year on the cathedral building. This tax was imposed by the crown and was unique to the city of Cordoba. It was probably instituted not only to make use of Mudéjar expertise but also to make up for the cathedral chapter's relative poverty, especially vis-à-vis the monumental task of repairing and maintaining such a large building. At the time, Mudéjar craftsmen