The First Barbary War (1801–1805), also known as the Tripolitanian War and the Barbary Coast War, was the first of two Barbary Wars between the United States and the four North African Muslim states known collectively as the "Barbary States". Three of these were nominal provinces of the Ottoman Empire, but in practice autonomous: Tripoli, Algiers, and Tunis. The fourth was the independent Sultanate of Morocco. The cause of the war was pirates from the Barbary States seizing American merchant ships and holding the crews for ransom, demanding the U.S. pay tribute to the Barbary rulers. United States President Thomas Jefferson refused to pay this tribute.