' s ▁borders ▁were ▁red ra wn , ▁following ▁the ▁decision ▁taken ▁at ▁the ▁Te her an ▁Conference ▁of ▁ 1 9 4 3 ▁at ▁the ▁ins istence ▁of ▁the ▁Soviet ▁Union . ▁Poland ▁lost ▁ 7 7 , 0 0 0   km 2 ▁of ▁territory ▁in ▁its ▁eastern ▁regions ▁( K res y ), ▁gain ing ▁instead ▁the ▁smaller ▁but ▁much ▁more ▁industrial ized ▁( how ever ▁ru ined ) ▁so - called ▁" Reg ained ▁Territ ories " ▁east ▁of ▁the ▁O der - Ne isse ▁line . ▁ ▁Administration ▁ ▁The ▁Polish ▁People ' s ▁Republic ▁was ▁divided ▁into ▁several ▁vo iv odes hips ▁( the ▁Polish ▁unit ▁of ▁administrative ▁division ). ▁After ▁World ▁War ▁II , ▁the ▁new ▁administrative ▁divisions ▁were ▁based ▁on ▁the ▁pre - war ▁ones . ▁The ▁areas ▁in ▁the ▁East ▁that ▁were ▁not ▁an nex ed ▁by ▁the ▁Soviet ▁Union ▁had ▁their ▁borders ▁left ▁almost ▁un changed . ▁New ly ▁acquired ▁territ ories ▁in ▁the ▁west ▁and ▁north ▁were ▁organ ised ▁into ▁the ▁vo iv odes hips ▁of ▁Sz cz ec in , ▁W roc ław , ▁O ls zt yn ▁and ▁partially ▁joined ▁to ▁G da ń sk , ▁Kat ow ice ▁and ▁Poz na ń ▁vo iv odes hips . ▁Two ▁cities ▁were ▁granted ▁vo iv odes hip ▁status : ▁Wars aw ▁and ▁Ł ód ź . ▁▁ ▁In ▁ 1 9 5 0 , ▁new ▁vo iv odes hips ▁were ▁created : ▁K osz alin ▁- ▁previously ▁part ▁of ▁Sz cz