Eventually, the Legion was disbanded in October 1915 and reorganized into the Polish Rifle Brigade.In 1795 Poland was partitioned between the Kingdom of Prussia, the Austrian and Russian Empires.

[1][2]In the Russian Empire, efforts of Witold Ostoja-Gorczyński, supported by the command of the Southwestern Front, resulted in a growing group of Polish volunteers gathering from October and November 1914 first at Chełm and Brest, and later at Puławy.

In January 1915 Polish National Committee threw its support behind the initiative, and colonel Antoni Reutt was nominated for the organization's commander.

[3] By January 1915 the Legion has finished organizing, at that time numbering about 1,000 volunteers; an equivalent of an Imperial Russian Army infantry battalion (in February it would be divided into four companies).

[3] The reorganization was a result of efforts by Colonel Rządkowaski and others aiming at increasing the size of the Polish forces in the Russian Army.