The Belokranjska Detachment had its origins in the partisan group formed in early April 1942 near the village of Popovici.  The group spent the month of May near the village of Dragomlje northeast of Ljubljana and were joined by new volunteers from Metlica, Graz and Vinica.  The group then merged with the Gorjanski battalion and by summer of 1942 it had grown into the Belokranjska Detachment.