The military edge that technological innovations had given European soldiers was the first and most visible sign of the new order. On October 24, 1746, on the estuary of the Adyar river, in the middle of what is now southern Chennai, the eldest son of the Nawab of the Carnatic, Mahfuz Khan, tried to block the passage of 700 newly-recruited French sepoys. These sepoys were the very first Indian troops to be trained up in modern infantry techniques by a European trading company. In just a few minutes, with the help of sustained musketry, their infantry drawn up in ranks, file-firing and using grapeshot and bayonets at close quarters in a way that had never before been seen in India, the 700 sepoys beat off an attack by the over 10,000 Mughal cavalry troopers. The battle of Adyar river proved a turning point in Indian history. Only two French sepoys were killed, while Mughal casualties were over 300. For the first time, techniques of 18th-century European warfare, developed in the Prussia of Frederick the Great, and tested on the battlefields of France and Flanders, had been tried out in India. It was clear that nothing in the Indian armoury could match their force. The trained sepoy with his file-firing muskets and hollow squares, and supported by artillery quick-firing grape and canister shot, would be an unstoppable force in Indian warfare for the next century.