Bayan mutuwar Bolesław I the Brave, manyan manufofinsa sun haifar da matsin lamba kan albarkatun ƙasar Poland ta farko, wanda ya kai ga rugujewar masarautu.Casimir I the Restorer ne ya fara farfadowa, wanda ya yi mulki daga 1039 zuwa 1058. Ɗansa, Bolesław II Mai karimci, duk da haka, ya fuskanci ƙalubale masu yawa a lokacin mulkinsa daga 1058 zuwa 1079, ciki har da wani mummunan rikici da Bishop Stanislaus na Szczepanów.Kisan bishop da Bolesław ya yi, bayan fitar da shi daga zargin yin zina, ya tunzura sarakunan Poland tawaye, wanda ya sa Bolesław ya yi hijira kuma ya yi hijira.Rarrabawar Poland ta kara tsananta bayan 1138 lokacin da Bolesław III, a cikin Alkawarinsa, ya raba mulkinsa tsakanin 'ya'yansa maza, wanda ya haifar da raguwar ikon sarauta da rikice-rikice na cikin gida akai-akai a cikin ƙarni na 12th da 13th.A wannan zamanin, fitattun mutane kamar Casimir II the Just a cikin 1180 sun nemi ƙarfafa mulkinsu ta hanyar daidaitawa tare da Coci, yayin da marubuci Wincenty Kadłubek ya ba da ƙarin bayanan tarihi a kusa da 1220.Ƙungiyoyin cikin gida sun sa Poland ta kasance cikin haɗari ga barazanar waje, wanda aka kwatanta da Teutonic Knights ' mamayewa bisa umarnin Konrad I na Masovia a 1226, da farko don yaƙar arna na Baltic Prussian amma ya haifar da rikice-rikice na tsawon lokaci.Mamayewar Mongol da suka fara a shekara ta 1240 sun ƙara dagula yankin, tare da gagarumin shan kashi a yakin Legnica a shekara ta 1241. Duk da waɗannan ƙalubalen, wannan lokacin kuma ya sami ci gaban tattalin arziki da ci gaban birane, inda Wrocław ya zama birni na farko na Poland a cikin 1242 da kuma An kafa garuruwa da yawa a ƙarƙashin Dokar Magdeburg.Kokarin sake hadewar Poland ya samu karbuwa a karshen karni na 13, tare da takaitaccen mulkin Duke Przemysł II a matsayin sarki a shekara ta 1295 wanda ke nuna alamar maido da sarauta na dan kankanin lokaci.Sai da Władysław na I the Elbow-high ya hau a cikin 1320 cewa an sami ƙarin ci gaba mai mahimmanci don haɗuwa.Ɗansa, Casimir III mai girma, wanda ya mulki daga 1333 zuwa 1370, ya ƙarfafa da kuma faɗaɗa daular Poland sosai, ko da yake hasara irin su Silesia ya ci gaba.Casimir III ya kuma kara inganta hadewar al'ummomi daban-daban, inda a shekara ta 1334 ya tabbatar da alfarmar al'ummar Yahudawa da Bolesław the Pious ya kafa a shekara ta 1264, ta haka ya karfafa matsugunan Yahudawa.Har ila yau, mulkinsa ya ga farkon cin nasara na Red Ruthenia a 1340 da kuma kafa abin da zai zama Jami'ar Jagiellonian a 1364, yana nuna wani lokaci mai mahimmanci na al'adu da yankuna duk da kalubalen da ake fuskanta.