Bombardment of Algiers ( 1816 ) The Bombardment of Algiers ( 27 August 1816 ) was an attempt by Britain to end the slavery practices of the Dey of Algiers . An Anglo - Dutch fleet under the command of Admiral Lord Exmouth bombarded ships and the harbour defences of Algiers . Although there was a continuing campaign by various European and the American navies to suppress the piracy against Europeans by the North African Barbary states , the specific aim of this expedition was to free Christian slaves and to stop the practice of enslaving Europeans . To this end , it was partially successful as the Dey of Algiers freed around 3 , 000 slaves following the bombardment and signed a treaty against the slavery of Europeans . However , the cessation of slavery did not last long . Background . Following the end of the Napoleonic Wars in 1815 , the Royal Navy no longer needed the Barbary states as a source of supplies for Gibraltar and their fleet in the Mediterranean Sea . Britain exerted considerable political pressure exerted to force the Barbary states to end their piracy and practice of enslaving European Christians . In early 1816 , Exmouth undertook a diplomatic mission , backed by a small squadron of ships of the line to Tunis , Tripoli , and Algiers to convince the Deys to stop the practice and free the Christian slaves . The Deys of Tunis and Tripoli agreed without any resistance , but the Dey of Algiers was more recalcitrant and the negotiations were stormy . Exmouth believed that he had managed to negotiate a treaty to stop the slavery of Christians and returned to England . However , due to confused orders , Algerian troops massacred 200 Corsican , Sicilian and Sardinian fishermen who were under British protection just after the treaty was signed . This caused outrage in Britain and Europe , and Exmouth ' s negotiations were seen as a failure . As a result , Exmouth was ordered to sea again to complete the job and punish the Algerians . He gathered a squadron of five ships of the line , one 50 - gun fourth - rate ship ( HMS " Leander " ) , four frigate s ( HMS " Severn " , " Glasgow " , " Granicus " and " Hebrus " ) , and five bombs ( HMS " Belzebub " , " Fury " , " Hecla " and " Infernal " ) . — 100 guns — was his flagship and Rear Admiral David Milne was his second in command aboard , 98 guns . This squadron was considered by many to be an insufficient force , but Exmouth had already unobtrusively surveyed the defences of Algiers : he was very familiar with the town , and was aware of a weakness in the field of fire of the defensive batteries . He believed that more large ships would have interfered with each other without being able to bring much more fire to bear . In addition to the main fleet , there were four sloops ( HMS " Heron " , " Mutine " , " Cordelia " and " Britomart " ) , eight ships ' boats armed with Congreve rockets , and some transports to carry the rescued slaves . When the British arrived in Gibraltar , a squadron of five Dutch frigate s ( " Melampus " , " Frederica " , " Dageraad " , " Diana " and " Amstel " ) and a corvette — led by Vice - Admiral Theodorus Frederik van Capellen — offered to join the expedition . Exmouth decided to assign them to cover the main force from Algerian flanking batteries , as there was insufficient space in the mole for the Dutch frigates . Plan of attack . The day before the attack , the frigate " Prometheus " arrived and its captain Dashwood attempted to secretly rescue the British Consul and his wife and infant . Some of the rescue party was discovered and arrested . The attack was described by the US Consul . The plan of attack was for the larger ships to approach in a column . They were to sail into the zone where the majority of the Algerian guns could not be brought to bear . Then , they were to come to anchor and bombard the batteries and fortifications on the mole to destroy the defences . Simultaneously , — 50 guns — was to anchor off the mouth of the harbour and bombard the shipping inside the mole . To protect " Leander " from the shore battery , two frigates — and — were to sail inshore and bombard the battery . Bombardment . Exmouth in " Queen Charlotte " anchored approximately off the mole facing the Algerian guns . However , a number of the other ships , notably Admiral Milne aboard HMS " Impregnable " anchored out of position , in the case of Milne ' s ship 400 yards from where it should have been . This error reduced the effectiveness of these ships and exposed them to fiercer Algerian fire . Some of the other ships sailed past " Impregnable " and anchored in positions closer to the plan . The unfortunate gap created by the misplaced HMS Impregnable was closed by the frigate HMS Granicus and the sloop Heron . In their earlier negotiations , both Exmouth and the Dey of Algiers had stated that they would not fire the first shot . The Dey ' s plan was to allow the fleet to anchor and then to sortie from the harbour and board the ships with large numbers of men in small boats . But , Algerian discipline was less effective and one Algerian gun fired a shot at 15 : 15 . Exmouth immediately began the bombardment . The Algerian flotilla made an attempt to board but thirty - three of their boats were sunk . After an hour , the cannon on the mole were effectively silenced , and Exmouth turned his attention to the shipping in the harbour , including a number of naval vessels of frigate size or smaller , which were destroyed by 19 : 30 . Although the fleet also bombarded the city , there was comparatively little damage as the construction of the houses meant that cannon balls passed through the walls , leaving a neat hole without destroying them . The explosive mortar shells and rockets caused some destruction to domestic buildings , and the shipping in the harbour burned so fiercely that the warehouses nearby caught light and were burnt down . At 20 : 00 , Milne asked that a sloop that had been fitted out as an explosion vessel , with 143 barrels of gunpowder aboard , be used against the " Lighthouse battery , " which was mauling his ship . The vessel was exploded , but to little effect and against the wrong battery . Despite this , the Algerian batteries could not maintain fire and by 22 : 15 , Exmouth gave the order for the fleet to weigh anchor and sail out of range , leaving HMS " Minden " to keep firing to suppress any further resistance . By 01 : 30 the next morning , the fleet was anchored out of range . The wounded were treated , and the crew cleared the damage caused by the Algerian guns . Casualties on the British side were 16 percent killed or wounded . The allied squadron had fired over 50 . 000 round shot using 118 tons of gunpowder , and the bomb vessels had fired 960 explosive mortar shells . Result . The following day at noon , Exmouth sent the following letter to the Dey : " Sir , for your atrocities at Bona on defenceless Christians , and your unbecoming disregard of the demands I made yesterday in the name of the Prince Regent of England , the fleet under my orders has given you a signal chastisement , by the total destruction of your navy , storehouse , and arsenal , with half your batteries . As England does not war for the destruction of cities , I am unwilling to visit your personal cruelties upon the unoffending inhabitants of the country , and I therefore offer you the same terms of peace which I conveyed to you yesterday in my Sovereign ' s name . Without the acceptance of these terms , you can have no peace with England . " He warned that if they were not accepted , then he would continue the action . The Dey accepted the terms , not realising that they were a bluff , as the fleet had already fired off almost all of its ammunition . A treaty was signed on September 24 , 1816 . The Dey freed 1 , 083 Christian slaves and the British Consul and repaid the ransom money . Over 3000 slaves in total were later freed . After some time , Algiers and other Barbary states renewed their piracy and slavery , as they earned revenues from the ransoms for some European slaves and had a market for others .