▁east ▁German ▁territ ories ▁at ▁the ▁end ▁of ▁the ▁war , ▁while ▁many ▁Uk ra ini ans , ▁Rus yn s ▁and ▁Bel arus ians ▁lived ▁in ▁territ ories ▁incorpor ated ▁into ▁the ▁USS R . ▁Small ▁Ukrain ian , ▁Bel arus ian , ▁Slov ak , ▁and ▁Lith uan ian ▁minor ities ▁res ided ▁along ▁the ▁borders , ▁and ▁a ▁German ▁minor ity ▁was ▁concentr ated ▁near ▁the ▁south western ▁city ▁of ▁O pole ▁and ▁in ▁Mas uria . ▁Gr oups ▁of ▁Uk ra ini ans ▁and ▁Polish ▁Ruth en ians ▁also ▁lived ▁in ▁western ▁Poland , ▁where ▁they ▁were ▁force fully ▁res ett led ▁by ▁the ▁authorities . ▁ ▁As ▁a ▁result ▁of ▁the ▁migr ations ▁and ▁the ▁Soviet ▁Un ions ▁rad ically ▁alter ed ▁borders ▁under ▁the ▁rule ▁of ▁Joseph ▁St alin , ▁the ▁population ▁of ▁Poland ▁became ▁one ▁of ▁the ▁most ▁eth n ically ▁hom ogeneous ▁in ▁the ▁world . ▁V irt ually ▁all ▁people ▁in ▁Poland ▁claim ▁Polish ▁national ity , ▁with ▁Polish ▁as ▁their ▁native ▁tongue . ▁ ▁Military ▁ ▁World ▁War ▁II ▁▁▁ ▁The ▁Polish ▁People ' s ▁Army ▁( L WP ) ▁was ▁initially ▁formed ▁during ▁World ▁War ▁II ▁as ▁the ▁Polish ▁ 1 st ▁T ade usz ▁Ko ści usz ko ▁Infantry ▁Division , ▁but ▁more ▁commonly ▁known ▁as ▁the ▁Ber ling ▁Army . ▁Al most ▁half ▁of ▁the ▁soldiers ▁and ▁rec ruits ▁in ▁the ▁Polish ▁People ' s ▁Army ▁were ▁Soviet . ▁In ▁March ▁ 1 9 4 5 , ▁Red ▁Army ▁officers