The Horseshoe and Transverse Arches

The first Muslim adaptation and modification of the design of the arch occurred in the invention of the horseshoe type. Further development came in the 8th century when Muslims used, for the first time, the transverse arch in the Palace of Ukhaidir.

These arches are found in many mosques throughout the Muslim world. The horseshoe arch is mainly decoration. Whilst the transverse arch has a structural function. They are also a common feature in numerous buildings in Europe. Where did the come from and how?

The Horseshoe Arch

The first Muslim adaptation and modification of the design of the arch occurred in the invention of the horseshoe type. This was first employed in the Umayyads Great Mosque of Damascus (706-715, figure 1) (Briggs, 1924). There is a suggestion that the horseshoe form was derived from the symbolic use of primitive ages where it represented a superstitious emblem for many societies (Jairazbhoy, 1973).

Figure 1. Horseshoe arches, Ummayad Mosque in Damascus.

The use of the horseshoe as a protector against the evil eye in North Africa is still maintained to the present day. They are often mounted onto front of doors of houses. However, this conflicts with orthodox islamic beliefs.

Similar symbolic use is manifest in India and many parts of the world.

A symbol of sainthood and holiness, the horseshoe arch provided a better advantage allowing more height then the classical (semi-circular) arch as well as better aesthetic and decorative use.

Muslims used this curve form to develop their famous ultra-semicircular arch around which the whole of Muslim architecture evolved [1]. The ultra-semicircular arch is an improved version of the Roman semicircular arch in that it is much more circular in shape.

The introduction of the horseshoe into Cordoba (Great Mosque 756-796, figure 2) set the path for its transmission to Europe through the northern Christian regions of Andalusia. This process started with the Mozarabs
(Christian Spanish living in Andalusia) moving between Andalusia and Northern Christian parts of Spain. Among these were artists, scholars and builders and architects who brought with them Muslim methods of building, forms and motifs including the horseshoe arch (Trend, 1931).

The result was the appearance, in northern Spanish regions, of a large number of religious edifices in a Moorish style with horseshoe arches. For instance, St Miguel de Escalada, near Leon, was built by monks arriving from Cordoba in 913.

Figure 2. Horseshoe and cinqfoil arches on main facade Cordoba Mosque.

Among the features it had were the melon shaped domes and the horseshoe arches (Dodds, 1994).

The horseshoe arch had also been illustrated by Mozarabs in their illuminated manuscripts such as the one of Beatus of Lebana. Historic sources indicate that the illuminator of this manuscript, named Magins, worked at the monastery of St Miguel de Esacalda.

The church of St Cebrian de Mazote, also founded by Mozarab Cordoban monks in 921, reveals similar planning, structural and decorative elements of that of St Miguel de Escalada with a basilica plan, horseshoe arches, tripartite choir and horseshoe shaped apses (Dodds, 1994).

The Transverse Arch

Further development came in the 8th century when Muslims used, for the first time, the transverse arch in the Palace of Ukhaidir – Iraq (720-800) setting precedent for its universal use.

Figure 3. Arcade of tranverse arches in Mahdia Mosque (Tunisia, 11th century)

After the adoption of the pier as a replacement of the classical column, Europe embraced this arch in the 11th century. Here, the arch was thrown from each pier of the arcade to the wall of the aisle (figure 3).

There is no clear evidence on how and when this arch was transmitted to Europe where it is considered to be the first step revolutionising the way churches were built.

The use of the transverse arch over the nave not only provided greater safety and durability but also gave the final shape of the nave especially in terms of height and roof.

This feature represents a fundamental structural step in the process of development of Gothic. It led to the adoption of ribbed vaulting which progressively enabled the vaulting of the nave and evolving the compound.

End notes:

[1]. The Romans were the first to use it but Muslims improved its form.