The Final Act of the Congress of Vienna included clauses obligating all the Great Powers in Europe to put an end to slavery. When news of a massacre of Sicilian fishermen by Algerian pirates reached the UK, it caused a storm of outrage. Sicily was at the time allied to Britain, who regarded Sicilians almost as honarary British citizens. As there was no longer a standing fleet in the Mediterranean Sea, a small fleet, including "Cordelia", returned to deal with the Dey of Algiers in August 1816. The combined British and Dutch fleet arrived off Algiers and, in a last-ditch effort to avoid bloodshed, they and the Algerians agreed not to fire the first shot. The Dey, however, sent number of men in boats to board the allied fleet and one of the Algerian boats opened fire. The resulting British and Dutch bombardment reduced Algiers to rubble and smoking ruins by the time it stopped that evening. In the resulting treaty, the European slaves awaiting sale were freed and about £80,000 in ransom money, paid by the Kingdom of Sardinia, was repaid.