The First Chechen War occurred when Russian forces attempted to stop the southern republic of Chechnya from seceding in a two year period lasting from 1994 to 1996. Despite overwhelming manpower, weaponry, and air support, the Russian forces were unable to establish effective control over the mountainous area due to many successful Chechen guerrilla raids. Widespread demoralization of the Russian forces in the area prompted Russian President Boris Yeltsin to declare a ceasefire in 1996 and sign a peace treaty a year later.