The Evolution of Islamic Arches

Arches are important in Islamic architecture, because of their symbolic significance and how they allow builders to create mosques that reflect the importance of precepts such as unity, beauty and light in the Muslim faith. The earliest mosques were open courtyards surrounded by arcades, or a row of arches. This eventually developed into a hypostyle hall, or space with a series of pillars. In Islamic architecture, these rows of arches symbolize the division between sacred and secular space.

The first use of arches in Islamic architecture included rounded arches similar to those found in Roman and Byzantine architecture, but these quickly developed into the horseshoe arch. In the horseshoe arch, the half-circle of the arch starts to turn in on itself before meeting the top of its supporting columns. The hypostyle hall in the Great Mosque at Cordoba, Spain, is a classic example of this type of arch. The shape of the horseshoe arch allowed architects to achieve greater height in the arches and it gave an opportunity for greater visual pattern and rhythm in the design.

The use of the transverse arch, in which the arch structurally spans the space between a pillar and the wall instead of another pillar, allowed architects to use slimmer pillars instead of thick columns in arcades. This innovation was adopted by European architects and eventually used in many Gothic cathedrals. Coupled with the four-centered arch -- a low, slightly pointed arch shape that has a center of gravity below the crown of the pillars -- transverse arches allowed Islamic architects to cover large spaces and led to the development of the pointed arch.

Many art historians believe the pointed arch originated in Islamic architecture. As early as The Dome of the Rock, built in 691, one sees arches with a slight point. The pointed arch had a major architectural advantage in that it centered the load-bearing thrust of the building on a vertical point, so that more of the building's weight could be supported on the exterior, usually with the use of buttresses, instead of with walls and interior columns. This allowed for thinner pillars, higher ceilings, the support of larger domes and overall gave the building a lighter, more open feel.

Sometimes called the cusped arch, multifoil arches contain arches within arches. This style of arch was very common in Moorish architecture and some examples can be found in the Great Mosque in Cordoba, alongside horseshoe arches. The main architectural benefit to multifoil arches is decorative -- like horseshoe arches, they provide opportunity for greater visual pattern and rhythm; and indeed the shape of multifoil arches was completely removed from arches to become a pattern motif on some buildings. But, like the pointed arch, multifoil arches also centered the thrust of the weight they carried to a single vertical point, which allowed for all the structural benefits of a pointed arch.