The murders of Patrick Vans Agnew and Lieutenant William Anderson on 20 April 1848 signaled the beginning of a Punjab-wide Sikh rebellion which soon became the Second Anglo-Sikh War. Initially, the East India Company was unprepared to deploy their army to the Punjab which meant that their political officers, including Nicholson, were completely isolated and effectively on their own in trying to maintain the British presence in the Punjab. It was in this vulnerable position that Nicholson was to display his soon to be characteristic nature of acting decisively and on his own initiative. He left Peshawar with a troop of irregular Pakthun horsemen and rode straight for the vital fort at Attock which, if controlled by the enemy, could sever the British line of communication. Upon arrival to the fort at first light, Nicholson rode straight past the stunned Sikh sentries guarding the main gate. When the Sikh sepoys further inside the fort raised their weapons against him, Nicholson leaped from his horse and wrestled the musket away from the nearest sepoy before shouting at them to lay down their arms and leave the fort, which the stunned Sikh garrison promptly did. This action, which was to become the first of Nicholson's famed exploits among the Sikhs, had enabled him to secure the vital fort without firing a single shot. Nicholson followed up this action just days later when he heard a Sikh infantry regiment were moving through the Margalla Hills in order to join the rebellion. Nicholson left Attock with his trusted irregulars and met the Sikh force camped at a Muslim cemetery. Nicholson rode up to the enemy camp and demanded to speak with their Colonel whom he gave one hour to submit their loyalty to him and be spared or else be destroyed "to a man". The Sikhs argued for an hour in front of the imposing figure of Nicholson, who sat motionless on his horse for the entire duration. Upon the hour mark, the Sikhs returned to Nicholson and declared their willingness to submit to his authority, thus cementing the growing legend of Nicholson among the Sikh population.