Rethel (rətĕlˈ) [key], town (1993 est. pop. 8,639), Ardennes dept., N France, on the Aisne River. It is a farm trade center with textile industries and plants making farm machinery. It was (13th cent.) the seat of a county held by the courts of Champagne, and passed (1384) to the house of Burgundy. It was raised to a duchy (1581) and acquired by the house of Gonzaga. The title was sold (1663) to the Mazarin family. Strategically located, Rethel has been the scene of much fighting throughout history. It suffered extensive damage in both World Wars.