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 Segeju and went home. This stimulated the Portuguese to take over Mombasa a third time in 1589, and four years later they built Fort Jesus to administer the region. Between Lake Malawi and the Zambezi mouth, Kalonga Mzura made an alliance with the Portuguese in 1608 and fielded 4,000 warriors to help defeat their rival Zimba, who were led by chief Lundi. After the building of Fort Jesus Mombasa was put by the Portuguese under the rule of members of the ruling family of Malindi. In 1631 Dom Jeronimo the ruler of Mombasa slaughtered the Portuguese garrison in the city