The earliest glazed ware in al-Andalus is dated to the Emiral period (c. AD 850-875) and is not until the Caliphate of Córdoba (AD 929-1031) that a distinctive polychrome tin glaze started being produced. A short transition period (c. AD 875-925) in which elaborate monochrome and bichrome transparent glazes wares coexist with polychrome transparent and tin opaque glazed wares has been identified. The existence of a polychrome lead transparent glaze production in al-Andalus wares is demonstrated; it has distinctive composition and methods of production from monochrome and bichrome wares, and shares a distinctive absence of foot and overglaze application of the decorations with the tin-opacified wares. With regard to the possible routes of the introduction of the polychrome lead and tin glazes into the western Mediterranean the Tunisian connection seems completely discarded. Moreover, and although some similarities between the Cordoba and the Abbasid productions such as similar tin glaze recipe and decorative patterns and use of lead glazes, can be traced, the dissimilarities, such as, the use of overglaze decorations, absence of alkali transparent glazes, variances in the tableware shapes and absence of foot, are still more important, and do not support a clear link between them.