Prior to the construction of Fort Jesus, the Portuguese colonial headquarters was an unfortified factory at Malindi, located at the mouth of the Galana River and the Indian Ocean, about 120 km northeast of Mombasa. The main objective behind the fort was to prevent the Turks from creating a base in East Africa along the Africa-India trade route. Between 1585 and 1588, Turkish raids reinforced this political sentiment; in 1593, after nearly a century in East Africa, the Portuguese initiated the planning and construction of a military fort in Mombasa.
Fort Jesus is built on top of a coral ridge that extends east-west from the mouth of the Mombasa harbor. The siting of the fort was determined principally by two factors: one, that any ship entering the harbor should come within point blank range of the fort guns and artillery; and two, that the fort be situated where small boats could land supplies in the bay area during an emergency or siege. At the present, the Old Town of Mombasa is located north of the fort, and the modern city is to the south. The fort itself is sited along a northeast-southwest axis, with its seaward face to the northeast.
The medieval design of the fort emphasizes symmetry and a schematic resemblance to the human body, and its layout reflects Portugese fortification tactics. However, many historians also note that the fort's design demonstrates an affinity with Indian fortresses rather than with other similar colonial Portuguese constructions in Africa. It is also noteworthy that the fort's original plan is stylistically similar to English fortifications built ca. 1540, as well as to Italian sixteen-century fortresses.
Quadrilateral in plan, the fort has four wide bastions at each corner (Sao Matias and Sao Mateus to the sea, Sao Filipe and Sao Alberto to land) and a rectangular projection between the two seaward bastions. Its overall dimensions are 130 meters across the northeastern harbor front (not including the outwork) and 99 meters across the bastions on the landward side. The fort is built around a rock core on rock foundations; two-thirds of the ramparts are solid coral, forming a nearly vertical face on the fort's seaward side. This has rendered the fort impervious to many siege scenarios.
Access and perimeter: The fort's main gate was reached from land by a wooden gangway across the dry ditch (a drawbridge was never added to the fort) located in the lee of S. Matias. Two subsidiary gates in the east wall of the rectangular projection allowed supplies to reach the fort by sea. The fort's outwork, a series of walled structures with two gates and entry points, lies closest to the coastline. Above the outwork is the fort's rectangular projection. Moving clockwise along the perimeter of the site from the bastion of Sao Mateus, the ground level rises dramatically and then descends into a ditch. Continuing clockwise, this ditch leads to the fort counterscarp (a stone walling lining the earth down to the foot of the ditch). This counterscarp leads into the first corner of the fort, where the bastion of S. Alberto is located. Here, a cavalier faces the bastion's longwall. Below this bastion lie the fort caves, which have yet to be fully investigated. Between S. Alberto and the adjacent bastion of S. Filipe, the ground level rises and the counterscarp of the ditch continues. Another cavalier is located at S. Felipe. Completing the exterior circuit along the perimeter of the fort, the ditch from S. Felipe leads down into to a depression and a flattened area that is the modern-day car park and causeway at the fort site. This is also the location of the outer and inner gates, and a procession that leads into the gatehouse and an open space flanked on either side by guardrooms. The fort's dry ditch, ten feet wide on the east and thirty feet wide on the west, was never completed and also constitutes the fort's most defective design element. The eastern end of the ditch was left relatively open; the southeastern end of the ditch becomes open ground, exposing the S. Mateus bastion to direct ground-level assault.
History: The fort's construction occurred over different periods: while construction began in 1593, it was hampered by poor planning and misallocated funds. Following the 1631 invasion by Sultan Yusif and the subsequent Swahili occupation of the fort until the Portuguese retook it in 1632, construction proceeded swiftly between 1633-1639, including a renovation completed in 1635 under the direction of fort captain Cabreira. The renovation included adding a new outer gate with protective elliptical projection housed under the bastion of S. Matias, an extra gun-platform directed beyond S. Mateus' seaward face that doubled the canon firepower facing the city's harbor entrance, adding gun-embrasures (angled openings cut into the parapet from which cannons could be fired) to the flanks of S. Mateus and S. Filipe, building two angled towers at the junction of the seaward rectangular projection, and fortifying the central seaward rectangular projecting by adding outwork between the projection and the water. This outwork served as a landing leading to the "Passage of Steps," and provided covering from the small sandy cove 90 meters to the south. Several gun-embrasures with a canon barrel pointing seawards were built into the outwork, and other arms could also be mounted here for additional defense. Under a special envoy of the Viceroy, Baltazar Marinho, the existing fort plans were altered and the walls became thicker and taller. Marinho also designed an additional entrance and gatehouse to create a double-entrance system with an antechamber space, so that on entering the first gate, one could not access the fort's interior directly. Marinho extended the construction to include lookouts on the four bastions and deepening the moat on the south side to make the S. Mateus bastion taller.
Omani Arabs besieged Fort Jesus between 1696-1698, and although the Portuguese reoccupied the fort briefly in 1728, it remained in Arab hands, passing first from the Omani to the Mazrui in 1741. Subsequently, the Mazrui and the Omani fought intermittently over the fort until the Omani Sultan regained it in 1837. Major changes were made in the 18th century: upper storys were added, S. Mateus was filled in, a guard room door leading to the main court was blocked, a small well with an open cistern and a washing place was added behind the great cistern, the portico behind the Captain's house was converted into a baraza (audience hall), and new houses were built atop the cavaliers on the south end of the fort. Over time, the barracks continued to be overcrowded, and the central courtyard space was filled with adobe structures for the soldiers and their dependents.
In the 19th century, the fort was mainly used as a barracks, and a small mosque was built against the south wall of the guardroom in S. Mateus. Later 19th century additions included six round watchtowers, one at each end of the rectangular projections that form the base of the fort's bastions. The source for their design is unknown, although their typology does resembles Portuguese turrets on the cavaliers. These watchtowers were used by the soldiers of the Omani Sultan to keep watch over the nearby countryside, where threats came mostly from the local Swahili population. Small details suggests that the watchtowers may have been built at different times: four have entrances with square lintels, while two (presumably older) towers had rounded lintels. These towers exhibited two roof types, one with a shallow cupola and one with a tall canonical cap.
In 1895 the British proclaimed a protectorate over the East African coast and subsequently occupied the fort as a prison. The Gulbenkian Foundation of Lisbon funded restorations to the fort in 1958, removing most traces of the British invasion, and so the contemporary condition of the restored fort shows no evidence of the period when it was used as a prison.
Gateway: The gateway to the fort is located on the flank of S. Matias on the western side of the site, under cover of the oreillons ("little ears," or the angled projections of the fort bastions). The gatehouse of the fort is housed in one of the oreillons, and is approached from the west. From the gatehouse, one passed under a round arch over a flight of stairs. The the decorative elements of the gatehouse suggest that it was a later addition: its crenellations are smaller and more irregular than those found in the rest of the fort.
The present inner gate was the original entrance to the fort had no voussoirs, unlike the gates to the Passage of Steps and the bastion of S. Mateus. This gate was built of plastered rubble and was situated in the angle of the north wall. A black stone inscription plaque above the gate records the dedication of the fort in the name of Jesus of Mombasa.
Ramparts: The original ramparts were 4.2 m thick, surmounted by a parapet 1.35 meters high and 2.4 meters thick. The wall assembly was rubble and earth, faced with coursed coral blocks measuring roughly 33 by 23 cm. The detailing of the parapet included an outer face sloping downwards at a 75 degree angle. The parapet itself was 2.66 m thick. Access to the parapet was limited to flights of steps in the middle of the west and north parapet walks. The intermediary rampart walls between the bastions contain structures overlooking the main court. Beginning in the east and moving clockwise, these include the modern-day museum (formerly the barracks) along the southern wall, the priest's residence, more barracks, the church, the cistern and the well along the western wall, and the barracks and toilets along the northern wall.
Bastions: The seaward bastion of Sao Mateus today holds the main gun-platform facing seawards, a guard room and a landing space flanked by a retaining wall. The seaward bastion of Sao Matias now houses the main entrance with double gates and an antechamber space, an elliptical projection, the gatehouse and guardrooms, the ticket office and the "L-shaped" room of the Captain's house. Rounded turrets link both S. Matias and S. Mateus to the projecting seaward wall. The fort parapet was designed with an outer, sharply angled vertical scarp leading down into a firestep and the parapet walkway below. These rose an average of one meter above the ground level in the main court of the fort.
The two landward bastions (S. Filipe and S. Alberto) were designed symmetrically, with deep re-entrant angles where they faced each other to provide screened gun positions and an effective field of crossfire. The two bastions also display characteristic oreillons. S. Alberto today holds an Arab-period house, a hangman's drop and the Warden's house, which now function as offices. Sao Filipe now houses an Arab-period house and the kitchens, formerly a guard room.
The fort had a total of 59 gun-embrasures; S. Felipe contained the most, at 14. 260 loopholes, most of which were located in the seaward-facing rectangular projection, were included in the fort, as were 9 sentry boxes and watchtowers set in coral. Of these boxes, two and a half were created by the Portuguese, and six and a half were added during the Arab period. These sentry boxes were located at intervals along the perimeter of the ramparts; the Portuguese sentry boxes are housed in the bastions of S. Filipe and S. Alberto on the landward side of the fort.
Rectangular seaward projection: The rectangular projection comprises the eastern perimeter of the main court, and holds the Passage of the Arches, the Passage of the Steps, the main part of the Captain's house, the Mazrui-period house, and the ammunition store. This projection overlooks the sea and is separated from the immediate coastline by the fort outwork.
Located in the north end of the rectangular projection facing the harbor, the three arches in the Passage of the Arches were built to support the weight of the Captain's residence. The passage measures 4.27 m at its widest point and 2.13 m at its narrowest point. The three arches divide the east-west passageway into sections measuring 4.27 meters, 7.31 meters, and 5.18 meters long. The middle (longest) section of the passage stood open to the sky.
The Passage of the Steps is found at the south end of the central rectangular projection, and consisted of over 22 steps (3.9 cm wide) cut into coral and descending towards an arched doorway. This doorway measured 1.45 meters high and 1.75 meters wide, with tapered voussoirs. The passage was bounded on the south by the south wall of the rectangular projection and on the north by a plaster retaining wall that culminated in a rounded top. This north wall had a niche that archaeologists believe housed a statue. The Passage of the Steps was originally open to the sky and later covered when the Captain's house was extended over to its south wall.
The Captain's house was built overlooking the harbor on top of the rectangular projection's platform above the fort's outworks. As such, the Captain's house had no protective parapet and was exposed to enemy fire from the harbor. Parts of the house were destroyed during the Arab siege of 1696-8, and were never restored. The decorative elements of the Captain's house were the most elaborate in the entire fort complex. Decorative elements included Swahili kidaka (plastered wall niches) that ran along the east wall at a height of 1.75 meters from the floor. The northeast corner of the structure housed a 91 cm high masonry pedestal where utensils could be washed. Recent archaeological excavations uncovered a red and black diamond decorative section on the plastered south wall of the south chamber. One of the main rooms in the Captain's house was the "L"-shaped room approached by two doorways in the west wall. This room, the largest in the house, is believed to have contained the greatest quantity of decorative elements and detailing. This room has also been described by the historian and cartographer Guillain as possibly functioning as a storeroom at some point during the history of the fort.
Later additions to this part of the fort included porticos with rounded arches topping two pillars projecting from the wall. Horizontal moldings capped by a slight cavetto wrapped the pillars. Each spandrel was coral, intricately carved with a marigold or sunflowers. In front of these pillars was a masonry bench. Walls on the south and west sides were painted with a dado of lotus tendrils in red and green. The lime concrete roof was supported by squared timbers carved with Arabic texts. Archaeologists have interpreted these texts as poetry and Koranic verses. This portico addition, known as the "lamp room" in earlier plans, became the Audience Room of the Mazrui.
Main court: The main, central courtyard measures two acres (0.8 ha) and is accessed via the main gate. The contemporary layout of the fort also incorporates new structures built under the Gulbenkian Foundation: a museum, the former curator's house (now the site offices), a ticket office, toilets, a refreshment room, and a shop.
Within the central court lay the residence and offices of the Captains of Mombasa. The garrison church lay situated close to the western rampart, and fort historians believe that it was, at various times over the fort's history, open to the public. Lines of soldiers' barracks lay along the north and south ramparts. The foundations of the northernmost line of buildings are still extant. On the western edge of the courtyard was the cistern (constructed in 1601), measuring 4.3 by 6 meters and about 12.2 meters deep. A well, 3.05 meters square, was later added between 1698 and 1728 behind the cistern during the Arab renovations of the fort.
The barrack blocks were built of coral blocks and culminated in pent-roofs. The northern block ran behind the north parapet walk and comprised 8 rooms divided in the middle by a flight of 3 steps leading up to the parapet walk. Little archaeological evidence has been found of the exact layout of the southern blocks, and this part of the site exists today as the museum building constructed under the Gulbenkian Foundation restorations.
The church was entered through the eastern end of the main court; its altar was located on the western end. The nave measured 13.87 by 7.16 meters and culminated in a flat roof supported by pilasters interspersed at intervals of 3.8, 4.5 and 3.5 meters down the long sides. The church nave comprised four low platforms, 1.5 meters long and 11 cm high. The sanctuary itself was 4 meters long and 5.3 meters wide and on the south side of the building was a baptistery. The interior of the sanctuary is believed to have been painted entirely in red ochre.
Decoration and materials: The entire fort was built out of large hewn coral blocks measuring roughly 13 inches by 89 inches. The walls were made of plastered earth and sometimes rubble. Decorative elements in the fort are largely confined to the Captain's house. In the Hall of the Mazrui, crafted stone benches and 18th century inscriptions were discovered during an archaeological excavation; however, modern graffiti also mars the walls of the hall. Literary and iconographic material was uncovered by archaeological exploration. To date, the most important finding has been that of the yellow ochre carbon wall paintings on the face of the platform in the S. Mateus bastion. This mural includes carved images of dhows, animals, churches, fish, chameleon and grotesque human figures. The fort also contains several commemorative coats of arms, including the Arms of Archduke of Hapsburg, the Arms of Mateus Mendes de Vasconcelos, and the Arms of King Philip II of Spain, for whom the bastions were named.
Consistent with Swahili architectural typology, the fort doors are intricately carved and exquisitely decorated, with sunken panels and palm-leaf decorations. One such door found by the modern ticket office near the inner entrance of the original gatehouse. This double door has a swinging center post; three layers of wood make up its laminate structure, which add to its weight and strength. It is studded with rows of brass spikes, and a Koranic text appears above it. Its decorative carvings resemble those of most Arab Swahili doors in Mombasa, with geometric and foliate decorative motifs.
The complex, once an icon of military strength and political power, now separates the Old Town and the modern city of Mombasa. Within the fort museum, displayed artifacts link the story of the Portuguese presence on the East African coast to the larger history of the region: the collection includes ceramics of Chinese, Persian, Arab and Portuguese origin, as well as a collection of East African earthenware, weaponry, and instruments.
Boxer, Charles Ralph. 1960. Fort Jesus and the Portuguese in Mombasa, 1593-1729. London: Hollis & Carter.
Kirkman, James S. 1981. Fort Jesus, Mombasa. Mombasa: National Museum of Kenya.
Kirkman, James. 1974. Fort Jesus: A Portuguese Fortress on the East African Coast. Oxford: Clarendon Press.
Nelson, William A. 1994. Fort Jesus of Mombasa. Edinburgh: Canongate Press.
Wilding, Richard. 1988. Panels, Pillars, and Posterity: Ancient Tombs on the North Kenyan Coast: a preliminary study. Mombasa [Kenya : s.n.].