Louis I ya gaji masarauta ta tsakiya da dukiya mai tarin yawa daga mahaifinsa.A cikin shekarun farko na mulkinsa, Louis ya kaddamar da yakin neman zabe a kan Lithuanians kuma ya maido da ikon sarauta a Croatia;Dakarunsa sun fatattaki sojojin Tatar, inda suka fadada ikonsa zuwa Tekun Bahar Rum.Lokacin da aka kashe ɗan'uwansa, Andrew, Duke na Calabria, mijin Sarauniya Joanna I na Naples, a shekara ta 1345, Louis ya zargi sarauniyar kisan gilla da azabtar da ita ya zama babban burin manufofinsa na waje.Ya kaddamar da yakin neman zabe sau biyu zuwa Masarautar Naples tsakanin 1347 zuwa 1350. Ayyukan son zuciya da zaluncin Louis da sojojin haya suka yi ya sa mulkinsa ba shi da farin jini a Kudancin Italiya.Ya janye dukkan sojojinsa daga masarautar Naples a shekara ta 1351.Kamar mahaifinsa, Louis ya gudanar da Hungary tare da cikakken iko kuma ya yi amfani da ikon sarauta don ba da gata ga fadawansa.Duk da haka, ya kuma tabbatar da 'yancin ɗan adam na Hungarian a Diet na 1351, yana mai da hankali ga daidaitattun matsayi na dukan masu daraja.A daidai wannan abincin, ya gabatar da tsarin entail da kuma hayar hayar da manoma za su biya ga masu gonakin, kuma ya tabbatar da haƙƙin yin motsi ga duk manoma.Ya yi yaƙe-yaƙe da Lithuanians, Serbia, da Golden Horde a cikin 1350s, tare da maido da ikon sarakunan Hungarian akan yankuna tare da iyakokin da suka ɓace a cikin shekarun da suka gabata.Ya tilasta wa Jamhuriyar Venice yin watsi da garuruwan Dalmatiya a shekara ta 1358. Ya kuma yi yunƙuri da yawa don faɗaɗa ikonsa akan sarakunan Bosnia, Moldavia, Wallachia, da wasu sassan Bulgaria da Serbia.Wadannan masu mulki wani lokaci suna son mika wuya gare shi, ko dai a karkashin tursasawa ko kuma da begen goyon bayan abokan adawar su na cikin gida, amma mulkin Louis a wadannan yankuna ba shi da tushe kawai a lokacin mafi yawan mulkinsa.Ƙoƙarin da ya yi na mai da al’ummar arna ko Orthodox zuwa Katolika ya sa ba a yi masa farin jini a jihohin Balkan ba.Louis ya kafa jami'a a Pécs a cikin 1367, amma an rufe ta cikin shekaru ashirin saboda bai shirya isassun kudaden shiga ba don kula da ita.Louis ya gāji ƙasar Poland bayan mutuwar kawunsa a shekara ta 1370. A ƙasar Hungary, ya ba wa manyan biranen sarauta damar tura alkalai zuwa babban kotun da ke sauraron ƙararrakinsu kuma ya kafa sabuwar babbar kotu.A farkon Western Schism, ya amince da Urban VI a matsayin halastaccen Paparoma.Bayan Urban ya kori Joanna kuma ya sanya dangin Louis Charles na Durazzo a kan kursiyin Naples, Louis ya taimaka wa Charles ya mallaki mulkin.