Louis d'Estrées, and forced out of Hanover. August 3–9 – French and Indian War: A French army under Louis-Joseph de Montcalm forces the English to surrender Fort William Henry. The French army's Indian allies slaughter the surviving men, women and children. August 11 – In the Battle of Delhi, the capital city of the Mughal Empire is retaken by Maratha Empire leader Raghunathrao from Najib ad-Dawlah, who flees to refuge in the royal palace, the Red Fort. August 30 – Seven Years' War – Battle of Gross-Jägersdorf: A Prussian army under Hans von Lehwaldt is defeated by the Russian army of Marshal Stepan Apraksin. September 6 – The life of Najib ad-Dawlah is spared by Raghunathrao upon the intercession of General Malhar Rao Holkar. Najib and his family are permitted to leave the Fort along with most of their property, and the Emperor Alamgir II is restored to the Mughal throne as a nominal ruler. September 8 – The Convention of Klosterzeven is signed at the Lower Saxony town of Bremervörde by the Duke of Cumberland following his defeat at the July 26 Battle of Hastenbeck by the French Army Marshal, the Duke of Richelieu. The treaty provides for the Army of the Electorate of Hanover to be reduced to a token force and for the French Army to occupy Hanover and most of northwest Germany. At the time, King George II of Great Britain is also the Elector of Hanover, and it is later said that "The terms proved worse than either George or his ministers had wanted or expected." September 13 – A column of troops from Sweden begins the surprise invasion of Prussia, setting up a pontoon bridge across the Peene River that marks the boundary between Swedish Pomerania and northern Prussia. After crossing at Loitz in the early morning hours, the troops march and begin the occupation of the undefended Prussian town of Demmin. Hours later, another Swedish infantry regiment charges across the border into the Prussian town of Anklam, where the city gate had been left open. September 23 – The "Raid on Rochefort" is carried out as a pre-emptive strike by Great Britain to neutralize France's Arsenal de Rochefort before the French Navy can carry out plans to invade England. Led by Royal Navy Admiral Edward Hawke, HMS Neptune and six other vessels sail in and capture the Île-d'Aix and its battery of cannons,