 Colonel (later General) Charles George Gordon, who was to become famous for his death in the Siege of Khartoum in 1885, lived in Fort House in the grounds of the fort between 1865-71 while he was overseeing the project.The fort had lost much of its importance by the turn of the 20th century.Advances in naval firepower meant that the principal line of defence for the Thames had been moved downriver to the batteries at Grain and Shoeburyness, where bigger guns with a longer range could control the entire estuary mouth.