Forces sent by Yusuf Karamanli of Tripoli to retake Derna from the Americans attack the city.

Yusuf Karamanli, Caramanli or Qaramanli or al-Qaramanli, (1766–1838) was the longest-reigning Pasha of the Karamanli dynasty of Ottoman Tripolitania. He is noted for his role in the Barbary Wars against the United States.

The Battle of Derna at Derna, Cyrenaica, was a military engagement 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.