roughly 200 to 300 Muslim Arab and Turkish mercenaries. The expedition's supplies were dwindling with Eaton reporting in 1805, "Our only provisions [are] a handful of rice and two biscuits a day." At one point, some of the Arabs in the expedition made a desperate attempt to raid the supply wagon but were beaten back by the Marines and a few Greek artillerymen, who used the expedition's lone cannon. Mutiny threatened the success of the expedition on several occasions. Between March 10 and March 18, several Arab camel drivers mutinied before they had reached the sanctuary of the Massouah Castle. From March 22 to March 30, several Arab mercenaries, under the command of Sheik el Tahib, staged mutinies. By April 8, when he crossed the border into Libya and Tripoli, Eaton had quelled the Arab mutinies. In late April, his army finally reached the port city of Bomba, on the Gulf of Bomba, some miles up the coast from Derna, where US Navy warships , and Hornet with Commodore Barron and Captain Hull were waiting for him. Eaton received fresh supplies and the money to pay his mercenaries. Battle On the morning of April 26, Eaton sent a letter to Mustafa Bey, the governor of Derna, to ask for safe passage through the city and additional supplies, but Eaton realized the governor probably would not agree. Mustafa reportedly wrote back, "My head or yours!" On the morning of April 27, Eaton observed a fort in Derna with eight guns. The brig USS Argus sent a cannon ashore to use in the attack. Captain Hull's ships then opened fire and bombarded Derna's batteries for an hour. Meanwhile, Eaton divided his army into two separate attacking parties. Hamet was to lead the Arab mercenaries southwest to cut the road to Tripoli and then attack the city's left flank and storm the weakly defended governor's palace. Eaton with the rest of the mercenaries and the squad of Marines would attack the harbor fortress. Hull and the ships would fire on the heavily-defended port batteries. The attack began at 2:45 p.m., with Lt. O'Bannon and his Marines leading the advance. O'Bannon led his Marines and 50 Greek gunners with the field piece from the Argus, but the gun's effectiveness was lessened after the firing crew carelessly left the ramrod in the barrel and fired it down range. The harbor defenses had been reinforced, and