Barbary Wars, 1801–1805 and 1815–1816
The Barbary States were a collection of North African states, many of which practiced state-supported piracy in order to exact tribute from weaker Atlantic powers. Morocco was an independent kingdom, Algiers, Tunis, and Tripoli owed a loose allegiance to the Ottoman Empire. The United States fought two separate wars with Tripoli (1801–1805) and Algiers (1815–1816), although at other times it preferred to pay tribute to obtain the release of captives held in the Barbary States.
The Barbary Wars
The practice of state-supported piracy and ransoming of captives was not wholly unusual for its time. Many European states commissioned privateers to attack each others’ shipping and also participated in the transatlantic slave trade. The two major European powers, Great Britain and France, found it expedient to encourage the Barbary States’ policy and pay tribute to them, as it allowed their merchant shipping an increased share of the Mediterranean trade, and Barbary leaders chose not to challenge the superior British or French navies.
https://history.state.gov/milestones/1801-1829/barbary-wars
