Fort Jesus is a fort located on Mombasa Island. Designed by Italian Giovanni Battista Cairati, it was built between 1593 and 1596 by order of King Felipe II of Castille, who also reigned as King Filipe I of Portugal and the Algarves, to guard the Old Port of Mombasa. Fort Jesus was the only fort maintained by the Portuguese on the Swahili coast, and is recognised as a testament to the first successful attempt by a Western power to establish influence over the Indian Ocean trade.

Cairato, the designer of the fort, was inspired by Italian architect Pietro Cataneo, while the master builder was Gaspar Rodrigues. The fort was Cairato’s last overseas work. Although the design of Fort Jesus is an example of Renaissance architecture, the masonry techniques, building materials and labour are believed to have been provided by the local Swahili people.

The fort was built in the shape of a man and is roughly square, with four bulwarks at its corners. The fort is considered a masterpiece of late Renaissance military fortification