On September 11, the Brigade withdrew towards Zambrów, next day it joined forces with Suwalska Cavalry Brigade, creating the so-called 'Group' of General Zygmunt Podhorski: "Zaza Cavalry 'Division'" ("Zaza" after "Zygmunt"). Depleted in continuous fighting, it headed eastwards to Białowieża, reaching the Białowieża Forest on September 16. After the Soviet invasion of Poland, remnants of the Brigade fought both Wehrmacht and Red Army troops, capitulating on October 6.