Even before their conversion to Islam, many Yao chiefs used Swahili Muslims as scribes and advisers. As a result of their strong trading contacts with Swahili-Arabs, many Yao adopted Islam and the two groups had cases of intermarriages in the past.
Before embracing Islam, Yao chiefs relied on Swahili Muslims for administrative and advisory roles. The Yao's trade connections with Swahili-Arabs facilitated the spread of Islam among the Yao people, and there have been documented cases of intermarriage between these communities in the past.