Stucco decoration in Islamic architecture

Stucco dome from Khirbat al-Mafjar, late Umayyad period (early 8th century),[4] showing Classical-inspired motifs carved in high relief

The use of carved stucco has been documented back to ancient times. Stucco decoration was used in Iran, Central Asia and the Greco-Roman Mediterranean,[5] though it was most strongly associated with Iranian architecture under the Parthians and Sasanians.[6] As the Islamic conquests of the 7th century captured Mesopotamia, Iran, and Central Asia and annexed them to the new Islamic empire, the long tradition of carved and painted stucco decoration in these regions was assimilated into early Islamic architecture.[4] The Umayyad caliphs (661–750 AD) made use of carved stucco in their architecture,[5] although it was of limited scope until the late Umayyad period.[12] Examples of early 8th century stucco survive at Umayyad sites like Khirbat al-Mafjar and Qasr al-Hayr al-Gharbi (whose portal is now at National Museum of Damascus).[12][2] As with other early Islamic sculptural decoration, the carved stucco decoration in the Umayyad period started out with an eclectic mix of styles originating in existing Classical, early Byzantine, and ancient Near Eastern artistic traditions.[2][4]

Panel of carved stucco wall decoration from Abbasid Samarra, Iraq, in the "beveled" style (9th century), showing flatter and more abstract motifs

It was only in the 9th century that a distinctively "Islamic" style of stucco decoration emerged.[4] Under the Abbasids, based in Iraq, stucco decoration developed more abstract motifs, as seen in the 9th-century palaces of Samarra. Three styles are distinguished by modern scholars: "style A" consists of vegetal motifs, including vine leaves, derived from more traditional Byzantine and Levantine styles; "style B" is a more abstract and stylized version of these motifs; and "style C", also known as the "beveled" style, is entirely abstract, consisting of repeating symmetrical forms of curved lines ending in spirals.[2][4][7]^{: 267–268} The Abbasid style became popular throughout the lands of the Abbasid Caliphate and is found as far as Afghanistan (e.g. Mosque of Haji Piyada in Balkh) and Egypt (e.g. Ibn Tulun Mosque).[2][4][7]^: 1

As the Abbasid realm fragmented in the following centuries, architectural styles became increasingly regionalized.[2] Towards the 11th century, muqarnas, a technique of three-dimensional geometric sculpting often compared to "stalactites", is attested across many parts of the Islamic world, often carved from stucco. It grew more popular from the 12th century onward.[13]

Stucco mihrab in the Great Mosque of Isfahan in Iran, with deeply-carved arabesques and inscriptions (early 14th century, Ilkhanid)

In the Greater Iranian region, a fairly distinctive style evolved from Abbasid models, employing stucco carved in high relief, especially in the decoration of mihrabs during the periods of Seljuk and Mongol domination.[2][7]^{: 121–122} Among the most notable examples are the mihrab of Friday Mosque of Ardistan (c. 1135 or 1160),[2] the Ilkhanid mihrab at the Great Mosque of Isfahan (1310),[14] and the mihrab of the Pir i-Bakran Mausoleum (early 14th century).[2] An earlier Mesopotamian tradition of muqarnas domes, as seen in the Imam ad-Dur Shrine near Samarra (1085–1090), was also passed on to Iran, with an important early example being the Tomb of 'Abd al-Samad at Natanz (1307–1308).[4] The Iranian fashion of stucco decoration spread to other nearby regions. In Indo-Islamic architecture (in the Indian subcontinent) it was commonly either sculpted or used to apply painted decoration, or both, although its importance declined in the mid-16th century. In the Deccan, stucco was often used to create round architectural medallions with plant motifs.[4] In Iran itself, high relief stucco carving grew less popular during the 15th century but then underwent a revival at the beginning of the 17th century, under the Safavids, when it was used in palace architecture.[4]

Stucco-carved mihrab in the Madrasa of al-Nasir Muhammad in Cairo (early 14th century, Mamluk)

Fine stucco carving was still employed in Egypt during the Fatimid period (10th to 12th centuries). The earlier Samarra styles evolved to incorporate more naturalistic forms. In carved Arabic inscriptions, for example, flowers and leaves were added to embellish the letters. One of the finest examples from this period is the mihrab of the al-Juyushi Mosque.[4][2] After this period, stucco decoration became less important and only occasional examples are attested under Mamluk rule, most of it in Cairo.[2][4] While it was common enough under the Bahri Mamluks (13th to 14th centuries), it was largely supplanted by other forms of decoration afterwards.[15]^: 90 The existing stucco examples from this period are nonetheless of high quality, as seen in the mihrab of the Madrasa of al-Nasir Muhammad, dated to 1304.[2][4] This monument also appears to demonstrate the influence or presence of craftsmen from other regions. The style of stucco decoration around the mihrab, for example, is reminiscent of Iranian stucco work in the style of Tabriz under the contemporary Ilkhanids.[15]^{: 154–155}[16]^: 226 The lavish stucco decoration of the madrasa's minaret, on the other hand, appears to involve contemporary Maghrebi styles and craftsmanship alongside local motifs.[16]^: 225[17]^: 77 Stucco decoration underwent a brief revival during the reign of Qaytbay (r. 1468–1496), when it was used again in interior decoration.[15]^: 90

Stucco carving in the al-'Attarin Madrasa in Fez, Morocco (14th century)

The Umayyad conquest of the Iberian Peninsula in the 8th century brought Islam to this region, which subsequently became known as Al-Andalus in Arabic. The establishment of a new Umayyad dynasty in Córdoba after 756, in the form of the Emirate of Córdoba (and the Caliphate of Córdoba after 929), led to the development of a distinctive style of Islamic architecture culminating in architectural masterpieces such as the Great Mosque of Córdoba. This style, popularly known as "Moorish" architecture,[18] was also influenced by other Islamic architectural traditions further east.[19] Archeological evidence near Kairouan in Tunisia and Sedrata in Algeria indicate that the Abbasid style of carved stucco was also introduced to the region of Ifriqiya.[4] Initially, however, the Abbasid style had little influence on art in al-Andalus, where stucco began to be used for decoration in the later half of the 10th century.[4]

The western Islamic architectural tradition continued to evolve over the subsequent Taifas period (11th century) and under the rule of North African empires, the Almoravids and the Almohads (11th to 13th centuries).[20][21] Stucco became the most common medium of decoration in the 11th century.[4] It was carved in high relief during the Taifas period (e.g. Aljafería Palace in Zaragoza) and during the Almoravid period (e.g. Qubba al-Barudiyyin in Marrakesh).[2] The elaborate decorative style of the Almoravids was initially restrained under their successors, the Almohads, whose monuments attest to a more subdued but elegant decoration. After them, however, architectural decoration reached new heights of lavishness in Al-Andalus and the western Maghreb.[4] The fashion evolved to favour stucco carved in shallow relief and to cover large surfaces along upper walls and under vaults.[2] Starting in the 13th century, the Nasrid dynasty in Granada constructed the palace complex known today as the Alhambra, which is replete with rich stucco decoration. Stucco decoration was also used profusely in the monuments of the Marinid dynasty in North Africa, particularly in madrasas, a number of which have survived in Morocco.[21]^: 188 The al-'Attarin Madrasa in Fez, for example, built by the Marinids between 1323 and 1325, is one of the finest examples of this decoration.[4] Comparable stucco decoration has also been found in the former palace of the Zayyanids in Tlemcen, Algeria.[22]^: 267

Mudéjar stucco decoration in the Royal Convent of Santa Clara in Tordesillas, Spain (14th century)

As Christian kingdoms progressively conquered the Iberian Peninsula, they continued to use the Islamic style, or "Mudéjar" style, in many of their new buildings. Moorish or Islamic-style plasterwork is found, for example, in 14th-century Castilian architecture such as the palace of Pedro I in the Alcázar of Seville, the Royal Convent of Santa Clara in Tordesillas (former palace of Alfonso XI), and the Jewish Synagogue of El Tránsito in Toledo. In these examples, Christian inscriptions and Castilian heraldry are also included against backgrounds of traditional Islamic arabesque and geometric motifs.[9] An important tradition of decorative plasterwork grew in Toledo, which fell to Castilian control in 1085. Many examples of Mudéjar plasterwork throughout Castile can be attributed to craftsmen from this city. From the 11th century to the mid-14th century, such plasterwork continued to be dominated by motifs of Islamic origin that are similar to contemporary Almoravid, Almohad, or Nasrid art. After the mid-14th century, other motifs were added to this repertoire, such as vine and oak leaves inspired by Gothic art and, later, figures of people and animals.[23]

Details of carving and polychromy in a muqarnas vault at the Palace of the Lions in the Alhambra, as seen today

In Nasrid art, the two basic techniques for creating stucco decoration were carving in situ and casting molds which were then attached to the structure. In situ carving was the most common method initially, but towards the early 14th century, during the reign of Muhammad III, molding became more standard.[8] Hand carving was accomplished by initially tracing design onto applied stucco layer and then carving using simple hand tools[8] of iron.[30] Casting allowed for more elaborate and intricate designs that could be repeated, creating systematic stylization.[8] Molds were commonly made from wood or plaster; the item was often cast in clay, then coated in gesso.[30] After molded pieces were attached to the walls, they were painted or whitewashed as needed.[8] Analysis of the original stuccos in the Alhambra show that Nasrid artisans were well versed in the properties of stucco and used different gypsum mixtures for carving and casting. For example, additives to slow drying and setting were used on stucco mixtures that were carved in place to allow artisans more time to complete their work.[25]^: 23[8]

Stucco was often polychromed. Age and weather, along with centuries of redecoration and restoration have significantly altered the original appearance of most stucco that date to the Nasrid period.[31] Current advances in analytical instrumentation that allows for in situ analysis of the stucco are yielding information about original pigments and techniques.[32] A further example of Nasrid artisans skill with stucco was their use of high purity gypsum coating that served both as a sealant and a preparatory stage for subsequent painting or gilding on the original stucco layer. The Alhambra has been the focus of recent investigations. The primary colors used on the stucco of the Alhambra were red, blue, green, golden, and black. Spectroscopic analysis of pigments attributed to original decoration of the Alhambra show cinnabar as the pigment used for red color. Lapis lazuli, a highly prized and expensive pigment, accounts for the blue. Malachite has been detected as the source of the green hues. Carbon black was used for black pigment.[33] Gilding, especially on the muqarnas, has been noted. The application of both pigment and gilding to these geometrically complex ceilings showed their knowledge and skill in optical allusion and spatial harmony. Investigations have focused on the muqarnas ornamented ceiling in the Hall of Kings in the Alhambra. Data is revealing the expansive use of two of the most expensive materials on this ceiling, lapis lazuli and gold leaf revealing the original dazzling opulence of the space.[34]