sentences:  As Kabul's principal fortress, Bala Hissar was an important site both in the First (1838–1842) and Second Anglo-Afghan War (1878–1880).The British envoy to Kabul, Sir Pierre Louis Napoleon Cavagnari was murdered inside the fort in September 1879 triggering a general uprising and the second phase of the Second Anglo-Afghan War.It was damaged during the Second Anglo-Afghan War when the British Residency was burned down, then later when the armoury exploded.