Horseshoe arch
[5] It appeared in pre-Islamic Sasanian architecture such as the Taq-i Kasra in present-day Iraq and the Palace of Ardashir in southwestern Iran (3rd century CE).
[10][12] In a 1991 publication, archeologist Stuart C. Munro-Hay suggests that these could be evidence that transmission of architectural ideas took place via routes not previously considered by scholars.
[20] Some tombstones from that period have been found in the north of Spain with horseshoe arches in them, eliciting speculation about a pre-Roman local Celtic tradition.
[5] According to Giovanni Teresio Rivoira, an archeologist writing in the early 20th century, the pointed variant of the horseshoe arch is of Islamic origin.
It was in Al-Andalus (on the Iberian Peninsula) and western North Africa (the Maghreb) that horseshoe arches developed their characteristic form.
[28]: 163–164 [33]: 43 The Umayyads of Al-Andalus, starting with the Emirate period, used horseshoe arches prominently and ubiquitously, often enclosing them in an alfiz (rectangular frame) to accentuate the effect of its shape.
[29] Its most distinctive form, however, was consolidated in the 10th-century during the Caliphal period, as seen at Madinat al-Zahra, where the arches consist of about three quarters of a circle and are framed in an alfiz.
[34] The Córdoban style of horseshoe arch spread all over the Caliphate and adjacent areas, and was adopted by the successor Muslim emirates of the peninsula, the taifas, as well as by the architecture of the Maghreb under subsequent dynasties.
[28]: 234 Art historian Georges Marçais attributed it in particular to Ifriqiya (present-day Tunisia), where it was present in earlier Aghlabid and Fatimid architecture.
[42][28] Horseshoe arches were also common in Ghurid and Ghaznavid architecture (11th-13th centuries) in Central Asia, though in this region they had sharp pointed apexes, in contrast with those of the western Islamic world.
[52] In addition to their use across the Islamic world, horseshoe arches became popular in Western countries in Moorish Revival architecture, which became fashionable in the 19th century.
