Mombasa modern period, Mombasa was a key node in the complex and far reaching Indian Ocean trading networks, its key exports then were ivory, millet, sesamum and coconuts. In the late pre-colonial period (late 19th century), it was the metropolis of a plantation society, which became dependent on slave labour (sources contradict whether the city was ever an important place for exporting slaves) but ivory caravans remained a major source of economic prosperity. Mombasa became the major port city of pre-colonial Kenya in the Middle Ages and was used to trade with other African port cities, the Persian Empire, the Arabian
Mombasa and defeated the relief force sent by the Portuguese. In 1632 Dom Jeronimo left Mombasa and became a pirate. That year the Portuguese returned and established direct rule over Mombasa. With the capture of Fort Jesus in 1698, the town came under the influence of the Imamate of Oman, subordinate to the Omani rulers on the island of Unguja, prompting regular local rebellions. Oman appointed three consecutive Governors (Wali in Arabic, Liwali in Swahili): Mombasa briefly returned to Portuguese rule by captain-major Álvaro Caetano de Melo Castro (12 March 1728 – 21 September 1729), then four new Omani Liwali until