How did Portuguese attacks affect East African coastal towns at the end of the 15th century?

At the end of the 15th century, the arrival of Portuguese ships under Vasco da Gama significantly disrupted the East African coast. Leveraging superior military and naval technology, the Portuguese launched a series of assaults on the region's city-states.1

The impact of these attacks included:

• Submission and Tribute: Coastal rulers were forced to pay tribute to the Portuguese king under threat of dethronement or death. By 1502, the sheikh of Kilwa and the ruler of Zanzibar were compelled to agree to these terms.1
• Destruction and Domination: The Portuguese sacked major centers, including Kilwa and Mombasa, and forced other towns like Lamu and Pate to submit. Within eight years of their arrival, they had established dominance over the coast and the vital trade routes leading to India.1
• Strategic Control: While they did not initially impose direct day-to-day rule, the Portuguese manipulated local politics to maintain dependency. They eventually established a more permanent presence, exemplified by the construction of Fort Jesus in Mombasa in 1593, which utilized European fortress architecture to solidify their control over the western Indian Ocean's commercial systems.12