To this end he negotiated an agreement with Wazir Akbar Khan, one of the sons of Dost Mohammad Barakzai, by which his army was to fall back to the British garrison at Jalalabad, more than 90 miles (140 km) away. As the army and its numerous dependents and camp followers began its march, it came under attack from Afghan tribesmen. Many of the column died of exposure, frostbite or starvation or were killed during the fighting.[4]