In May 1667 negotiations were in progress for a peace to end the Second Dutch War, 1665–1667, between the English and Dutch. The English erroneously anticipated an early settlement and did not mobilise their fleet for the summer, since they did not believe that the Dutch had done so. They also believed that such restraint would be read as a gesture of peaceful intent. However, peace negotiations did not run smoothly and the Dutch, finding agreement impossible, secretly and swiftly mobilised their fleet. Before the English were even aware of this the Dutch, under Lieutenant-Admiral Michiel de Ruyter, appeared in the Thames, captured Sheerness and, over three weeks, began to take or destroy ships of the English fleet laid up in the Medway. When they sailed for home they took with them the 'Royal Charles', 86 guns, and left three more of the finest ships burning. Others had been sunk to prevent the Dutch penetrating further up the river. This major naval disaster for England resulted in much better terms for the Dutch when the Treaty of Breda was signed some months later.