On 8 April 1992 the Croatian Defence Council (HVO) was formed and was the official military of Herzeg-Bosnia. A sizable number of Bosniaks also joined the HVO, constituting between 20 and 30 percent of the army. The legal rationale for the formation of HVO was seen in the laws of Yugoslavia that allowed citizens to organize their own self-defense when their government was unable or unwilling to defend them. Boban said that the HVO was formed because "thirteen Croatian villages in the municipality of Trebinje – including Ravno – were destroyed and the Bosnian government did nothing thereafter".