Kammala jumla mai zuwa: An kirkiro sashin ne a ranar 13 ga Maris, 1937, wanda aka kafa ta 23rd, 66th da 77th brigades; kwamandansa na farko shi ne Ernesto Güemes Ramos. Da farko an sanya shi ga Rundunar Sojoji ta IV, a watan Mayu 1937 ya zama wani ɓangare na Rundunar Sojoji ta III, a kan iyakar
Gabatarwar Madrid. Tsawon watanni da yawa rundunar ta kasance a can, tana iyakance kanta ga aikin garrison kuma ba ta shiga cikin ayyukan soja masu dacewa ba.