During the War of the First Coalition, Revolutionary France invaded the Austrian Netherlands, and with it, Luxembourg, yet again. In the years 1793 and 1794 most of the Duchy was conquered relatively fast and the French Revolutionary Army committed many atrocities and pillages against the luxembourgish civilian population and abbeys, the most infamous being the massacres of Differdange and Dudelange. However the Fortress of Luxembourg resisted for nearly 7 months before the Austrian forces holding it surrendered. Luxembourg's long defense led Lazare Carnot to call Luxembourg "the best fortress in the world, except Gibraltar", giving rise to the city's nickname ''the Gibraltar of the North''.