On 28 August 1993, Herzeg-Bosnia was declared a republic following the proposal of the Owen-Stoltenberg Plan, envisioning Bosnia and Herzegovina as a union of three republics. Its capital city was Mostar, which was then a war zone, and the effective control centre was in Grude. In March 1994, the Washington Agreement was signed that ended the conflict between Croats and Bosniaks. Under the agreement, Herzeg-Bosnia was to be joined into the Croat–Bosniak Federation, but it continued to exist until it was formally abolished in 1996.