Based on an inscription on one of its marble columns, the mosque is thought to originate from the 14th century, during the reign of the Marinid sultan Abu al-Hasan, though there is not much available information. In the late 18th century, the Alaouite sultan Mohammed ibn Abdallah built an adjoining madrasa while also restoring and expanding the mosque itself. The mosque was reportedly heavily restored and modified at the end of the 19th century as well. The mosque is named after the nearby Bab Guissa, a city gate which was in turn named after the 11th-century Zenata prince al-Guissa ibn Dounas who built the original gate by this name.
Description
Mosque
The mosque occupies a space of about 1440 square meters and is located just inside the northern city gate called Bab Guissa. This is a relatively elevated position compared to the rest of Fes el-Bali, and as a result the mosque's minaret is prominent on the northern skyline of the medina. The minaret is plain and mostly undecorated. On the mosque's eastern side, next to the base of the minaret, is the mosque's main entrance. The gateway is decorated with typical Moroccan motifs including interlacing semi-circles around the doorway's arch and a larger square frame with a band of darj-w-ktaf or sebka. Above the door is a carved and painted wooden canopy, also characteristic of traditional Moroccan architecture. Next to this entrance, and adjoining the city wall, is a small outdoor gallery with wall fountains for ablutions, decorated with mosaic tiles in geometric patterns as well as tiles painted with arabesques and Arabic calligraphy. The interior of the mosque is dominated by a relatively large courtyard or sahn, surrounded by galleries on three sides and by the main prayer hall on its southeastern side, all marked by large, slightly pointed horseshoe arches which are typical of medieval Moroccan mosques. The courtyard has a typical central fountain, but is also shaded by several fig trees, a much less typical feature. The main prayer hall is short and only two rows deep. The wall around the mihrab is richly decorated with carved stucco and, in its top portion, a row of stained glass windows with grilles of geometric patterns.
Funerary mosque annex
Behind the prayer hall and attached but secluded from the rest of the mosque is an interior prayer space used only for funerary rites and for prayers over the bodies of the deceased before burial. This type of annex to a mosque, called a Jama al-Gna'iz is not common to all mosques in the Islamic world, but similar annexes are attached to the Qarawiyyin Mosque and the Chrabliyine Mosque in Fes. It is designed to be separate from the main mosque so as to maintain the purity of the latter as a regular prayer space. This part of the mosque is accessed by another monumental portal on the south side of the complex, decorated with a radiating or semi-circular geometric pattern reminiscent of Almohad and Marinid gates. Since the Bab Guissa cemetery is located just outside the nearby city gate, it is likely that the mosque was well-situated to offer this type of service.
Madrasa
Adjacent to the mosque is the 18th-century madrasa built by sultan Mohammed ibn Abdallah. It is accessed through a door in the mosque's northern wall, but the building is located on the mosque's western or southwestern side. It is roughly the same length of the mosque but only half as wide. It consists of a two-story gallery around a long courtyard of 22 meters by 4.8 meters with a central fountain. Aside from the floor of the courtyard, which is paved with simple zellij mosaic tiles, this madrasa is essentially undecorated Bou Inania Madrasa or the slightly more contemporary. Today, the courtyard is also covered with modern light roof to keep out the rain. The galleries give access to the sleeping cells of the students. Seminars were conducted in the madrasa, and the mosque itself also hosted two teaching chairs. At the beginning of the 20th century the madrasa housed 40-60 students, mostly from the nearby mountain regions of Morocco. It is still in use today.
