The Battle of Derna at Derna, Cyrenaica, was the decisive victory in April–May 1805 of a mercenary army recruited and led by United States Marines under the command of U.S. Army Lieutenant William Eaton, diplomatic Consul to Tripoli, and U.S. Marine Corps First Lieutenant Presley Neville O'Bannon. The battle involved a forced 521-mile (839-km) march through the North African desert from Alexandria, Egypt, to the eastern port city of Derna, Libya, which was defended by a much larger force. Background In 1804, the former Consul to Tunis, William Eaton (1764–1811), returned to the Mediterranean Sea with the title of Naval Agent to the Barbary States. Eaton had been granted permission from the US government and US President Thomas Jefferson (1743–1826; served 1801–1809) to back the claim of Hamet Karamanli, the rightful heir to the throne of Tripoli who had been deposed by his brother Yusuf Karamanli, who had assassinated his older brother by shooting him in front of his mother. Hamet was out of the country at the time and decided to remain in exile. Upon his return to the area, Eaton sought out Hamet, who was in exile in Egypt. Upon locating him, Eaton made a proposal to reinstate him on the throne, and Hamet agreed to Eaton's plan. Commodore Samuel Barron (1765–1810), the new naval commander in the Mediterranean Sea, provided Eaton with naval support from several small warships of the US Navy's Mediterranean squadron: , commanded by Oliver Hazard Perry (1785–1819), , under Samuel Evans (c. 1785–1824), and , captained by Isaac Hull (1773–1843). The three vessels were to provide offshore bombardment support. A small detachment of seven US Marines was given to Consul Eaton commanded by First Lieutenant Presley O'Bannon, USMC (1776–1850). Eaton and O'Bannon based their operations at Alexandria, Egypt. With the help of Hamet Karamanli, they recruited about 400 Arab and Greek mercenaries. Eaton became self-appointed general and commander-in-chief of the combined multinational force. On March 8, 1805, Lieutenant Eaton (as self-designated general and commander in chief) began to lead his forces on a trek westward across the Libyan North African desert from Egypt. Their objective was the port city of Derna, the capital of the Ottoman province of Cyrenaica (now in eastern Libya). The mercenary forces were promised supplies and money when they reached the city. During the 50-day trek, Eaton became worried over the strained relationship between the Christian Greeks and the