In order to neutralise this objection and further the anti-slavery campaign, in 1816 Lord Exmouth was sent to secure new concessions from Tripoli, Tunis, and Algiers, including a pledge to treat Christian captives in any future conflict as prisoners of war rather than slaves and the imposition of peace between Algiers and the kingdoms of Sardinia and Sicily. On his first visit he negotiated satisfactory treaties and sailed for home. While he was negotiating, a number of Sardinian fishermen who had settled at Bona on the Tunisian coast were brutally treated without his knowledge. As Sardinians they were technically under British protection and the government sent Exmouth back to secure reparation. On August 17, in combination with a Dutch squadron under Admiral Van de Capellen, he bombarded Algiers. Both Algiers and Tunis made fresh concessions as a result.