History

Portugal established its presence on the East African coast from 1498, using Mombasa as a provisioning stop on the sea route to India. The decision to build Fort Jesus in 1593 reflected a shift from seasonal exploitation to permanent occupation: the fort was intended to secure Portuguese control over the entire Swahili coast trade network — the cotton textiles, ivory, gold, and enslaved people flowing from the African interior to the Indian Ocean commerce. Construction took three years and required the labour of hundreds of workers; the walls were built of coral rag quarried from the promontory itself, giving them the characteristic pale gold colour that distinguishes the fort in all its representations.

From 1631, when a Swahili sultan briefly seized the fort by deception, Fort Jesus entered a cycle of siege and counter-siege that would continue for two and a half centuries. The most consequential episode was the Omani siege of 1696–1698: Omani forces under the Imam of Oman blockaded the fort for thirty-three months while plague devastated the Portuguese garrison; only eleven Portuguese soldiers survived to surrender in December 1698. The Omanis held the fort until 1728, then lost it briefly to a Portuguese counter-attack, then regained it in 1729 — a final date that effectively ended Portuguese power on the East African coast. Thereafter the fort passed between the Omani sultans, the Mazrui dynasty (an Omani family that broke from the Sultanate), and — from 1837 — the Sultanate of Zanzibar, before the British took nominal control in 1895 and converted it to a prison in 1895, a role it retained until 1958.