What was the main cause of the development of the Swahili culture?

The main cause of the development of the Swahili culture was the interaction between Bantu-speaking African communities and Arab traders along the East African coast. This interaction, which began in the early centuries AD, led to the blending of African and Arabian cultural elements, resulting in the unique Swahili culture that emerged in the region. Trade, intermarriage, language, and religious practices all played a role in shaping the Swahili culture.