The (British) Army of the Indus, comprising 20,000 soldiers and twice that number of camp followers, had set off in the spring of 1839 to fight in the First Afghan War. It was January 13, 1842, and the 30-year-old Scot was all that remained of the British force that had invaded Afghanistan three years earlier. When a rescue party reached him, they found a shadow of a man, his head sliced open, his tattered uniform heavily bloodstained. He seemed more dead than alive but when asked; Where is the Army? Assistant Surgeon William Brydon managed to reply: I am the Army.
Below is a famous painting shows William Brydon on his horse, lone British escaped wrath of Afghan.