From the early 19th century, Abéché was at the centre of the Islamic slave trade in Chad and an important city in the developing of the religion in the region. Situated long the trans-Saharan trade route, many Islamic scholars and merchants travelled through the city. after the wells at
Ouara, the former capital, had dried out. In 1909, French troops invaded the Kingdom and established a garrison in Abéché, forcing the sultan to renounce his throne. At that time, Abéché was the largest city in Chad with 28,000 people, but major epidemics reduced the population to 6,000 in 1919. In 1935, the sultanate was restored by orders of the French government, and Muhammed Ouarada, heir to the throne after his father became king. On 25 November 2006, the city was taken by the
Union of Forces for Democracy, a rebel group that sought to depose president
Idriss Déby. Extensive looting took place during the night. On the same day, nearby
Biltine was captured by the
Rally of Democratic Forces, another rebel group. A day later, both cities were retaken by the Chadian army. On 30 October 2007, the city came to international attention when 17 French volunteers working for the charity
Zoé's Ark were arrested there for alleged
child abduction. ==Geography and climate==