Before its annexation by Germany the lagoons were a favourite resort of slavers, and stations were established there by Portuguese, British, French and German traders.
When driven from other parts of Guinea the slavers made this difficult and little known coast one of their last resorts, and many barracoons were built in the late years of the 18th century.
An English fort was built on Bance Island in the Sierra Leone estuary towards the close of the 17th century, but was soon afterwards abandoned, though for a long period the estuary was the haunt of slavers and pirates.
It was here that a party of Arab slavers, without warning or provocation, assembled one day when the market was busiest and commenced shooting the women, hundreds being killed or drowned in trying to escape.
By the Arab slavers whom he opposed he was also greatly admired, and was by them styled "the very great doctor."