In July 1798 Napoleon Bonaparte led a French expeditionary force across the Mediterranean to invade Egypt, then part of the Ottoman Empire. Initial landings were successful and the Battle of the Pyramids confirmed Bonaparte's control of the country. On 1 August however his fleet was destroyed by a British force under Sir Horatio Nelson at the Battle of the Nile on 1 August, isolating the French army in Egypt. The Admiralty initiated a major response, including dispatching a squadron under Commodore John Blankett to blockade the Egyptian Red Sea coast: there was concern in London that Bonaparte might proceed to attack India from Egypt, in conjunction with the Tipu Sultan and the armies of Mysore. Blankett's force arrived in December 1798, joined by a squadron sent by Rainier. Bonaparte had visited Suez early in the month, and plans had been drawn up for a small French Red Sea squadron, but Blankett's force and the regional supremacy it brought rendered these plans obsolete. Attacks were made on commercial shipping at Suez in April, and the entrance to the Red Sea was effectively blockaded by British occupation of Perim and Mocha, and in July 1799 Blankett ordered the frigates and "Fox" to destroy the French-held castle at Qusayr. The town was heavily bombarded, although attempts to make amphibious landings were driven off.