Fort Jesus is a fortress located in Mombasa, on Kenya’s coastline, at the entrance to the natural harbor that long made the city a hub of trade in the Indian Ocean. The structure was built between 1593 and 1596 on the orders of King Philip II of Spain, who at the time also ruled Portugal, to safeguard Portuguese interests along the Swahili coast. It was designed by the Italian architect Giovanni Battista Cairati, who worked on several military projects for the Portuguese Empire.

The fortress stands on a coral outcrop overlooking the ocean. Its layout reflects Renaissance military architecture adapted to the use of firearms. Seen from above, its shape has been described as resembling a human figure, with bastions positioned to defend against attacks from different directions. The walls, constructed from coral stone bonded with lime mortar, rise to more than fifteen meters in some sections. The complex originally included bastions, ramparts, gun emplacements, storage rooms, and water cisterns intended to sustain the garrison during sieges.

Fort Jesus became a focal point in the struggle for control of the East African coast. Throughout the seventeenth century, it endured several sieges. The most significant took place between 1696 and 1698, when forces from the Sultanate of Oman besieged the fort for nearly three years before capturing it from the Portuguese. Control of the site shifted between the Portuguese and the Omanis until the early eighteenth century, after which it remained under Omani authority. In the nineteenth century, the fort was used by local rulers and later by the British, who converted it into a prison following the establishment of their protectorate over the Kenyan coast.

Over time, the fortress lost its military role. In the mid-twentieth century, while Kenya was still under British colonial administration, restoration efforts were undertaken to preserve the structure. After independence in 1963, Fort Jesus became part of Kenya’s national heritage. It now houses a museum managed by the National Museums of Kenya, displaying archaeological finds such as ceramics, weapons, and objects linked to maritime trade between East Africa, the Arabian Peninsula, India, and Europe.

In 2011, Fort Jesus was inscribed on the UNESCO World Heritage List. The designation recognizes its role as a material record of cultural exchanges and commercial networks in the Indian Ocean, as well as the political transformations that shaped the Swahili coast from the sixteenth to the nineteenth century. Today, the site remains a central historical landmark in Mombasa and a resource for studying the long history of interaction between East Africa and other regions of the world.