Complex sentence: Trade with the interior of Cameroon was handled by the Duala people settled at the mouth of the Wouri River in the area now covered by the city of Douala, led by two "kings" representing the Bell and Akwa factions.
Split into simpler sentences: Trade with the interior of Cameroon was handled by the Duala people settled at the mouth of the Wouri River in the area now covered by the city of Douala. They were led by two "kings" representing the Bell and Akwa factions.