[citation needed] In the initial stage of the Bosnian War, the HVO fought alongside the Army of the Republic of Bosnia and Herzegovina (ARBiH) against the Army of Republika Srpska, but in the latter stage of the conflict clashed against its former ally, particularly in the Mostar area.

[4] the HVO was incorporated into the Army of the Federation of Bosnia and Herzegovina (VFBiH) in December 1995 by following agreement made after signing the Dayton Accords.

The HVO was established on 8 April 1992 in Grude by the political leadership of Croats, mainly members of Croatian Democratic Union as the official military formation of Herzeg-Bosnia.

[5] War broke out between Herzeg-Bosnia, supported by Croatia and the Croatian Defence Forces, and The Republic of Bosnia and Herzegovina.

[6] In March 1996, Herzeg-Bosnia ceased to exist as it was merged with the Federation of Bosnia and Herzegovina, and the HVO was reorganized as 1st Infantry (Guard) Regiment of the ARBiH.

While first three zones were grouped more or less together, with 2 enclaves, Usora, which was defended by the 110th Usora Brigade, and Žepče, which was defended by the 111th Žepče XP Brigade [hr], Posavina was completely isolated in northern Bosnia on right bank of Sava river around Orašje and was entirely dependent on support from Croatia.

In early 1993, the HVO Home Guard [hr] (Croatian: Domobranstvo) was formed in order to provide support for the brigades.

[7] The HVO forces became better organized as time passed by, but they started creating guards brigades, mobile units of professional soldiers, only in early 1994.