Queen Kahina led a decades long war against the Islamic conquest in the 7th century and built a castle here.
During the Barbary period there were many inter-town conflicts over water resources.
The French army reached Khenchela in 1850 after heavy fighting and strenuous resistance and set up a military administration. Organization of work on the city was undertaken. The first French settlers were allowed from 1878. Farms and plantations were built. In the process, farmers cleared a path for vegetation at the valley of Wadi Boughegal which in turn gave birth to natural grasslands, allowing cattle breeding and feeding the population with fresh dairy products.
In October 1905, the inauguration of the meter-gauge railway line from Aïn Beïda to Khenchela provided daily service with the north of the country. Military administration lasted until 1912.
In 1982, a mass grave containing more than 1200 corpses from the war of Algeria was discovered. It would be the largest ever discovered in Algeria. The authorities and the Algerian press attributed it to the French army, while others disputed this and suggested the victims may have been French harkis.[2]
Since the 20th century, Khenchela's population has grown particularly fast: 12 000 inhabitants in 1954, 28,000 in 1962, 70,000 in 1987 and 87,196 in 2002. This increase is partly explained by population displacement during the war in Algeria, the area being a refuge for resistance fighters. This has posed and continues to pose planning problems (housing, water, sewer, electricity).