Casimir III na Poland ya mutu a ranar 5 ga Nuwamba 1370. Louis ya isa bayan jana'izar kawunsa kuma ya ba da umarnin a kafa wani babban abin tunawa na Marmara na Gothic ga marigayin.An nada shi Sarkin Poland a cikin Cathedral na Cracow a ranar 17 ga Nuwamba.Casimir III ya so ubangidansa - ciki har da duchies na Sieradz, Łęczyca da Dobrzyń - ga jikansa, Casimir IV, Duke na Pomerania.Duk da haka, sarakuna da sarakunan Poland sun yi adawa da wargajewar Poland kuma an bayyana wa'adin Casimir III a matsayin mara amfani.Louis ya ziyarci Gniezno kuma ya sanya mahaifiyarsa 'yar Poland, Elizabeth, mai mulki kafin ya koma Hungary a watan Disamba.'Ya'yan kawunsa guda biyu da suka tsira (Anna da Jadwiga) sun raka shi, kuma an tura kayan ado na Polish Crown zuwa Buda, wanda ya haifar da rashin jin daɗi a tsakanin sababbin batutuwa na Louis.Matar Louis ta haifi 'ya mace, Catherine, a cikin 1370, shekaru goma sha bakwai bayan aurensu;an haifi ’ya ta biyu, Mary, a shekara ta 1371. Bayan haka Louis ya yi ƙoƙari da yawa don kare haƙƙin ’ya’yansa mata na gaje shi.