At that time, Arabs appeared in these areas, spreading Islam and Arab culture.

An excerpt from the article 32 facts about Uganda

The reigning Mutesa I adopted Islam and established contacts with other African states (Egypt and Zanzibar), as well as with the British. Missionaries began to arrive there in the mid-19th century, and in 1888 the British East Africa Company began its operations and took Buganda under its protectorate. In the early 20th century, the British protectorate expanded to cover the entire country.