Kammala wannan jumla: Shigar da Romania cikin Yaƙin a watan Agusta 1916 ya haifar da manyan canje-canje ga Jamusawa. An kori Janar Erich von Falkenhayn kuma aka tura shi don ya jagoranci sojojin Tsakiya a Romania, wanda ya ba da damar Hindenburg ya hau mulki. Sakamakon yaƙi da dukkan manyan ƙasashe a kan gaba mafi tsawo a Turai (kilomita 1600) kuma tare da ɗan taimako na ƙasashen waje (Rashawa 50,000 ne kawai suka taimaka wa 'yan Romaniya 650,000 a cikin 1916),
an ci babban birnin Romania a watan Disamba. An kuma kama Vlaicu III kuma aka tura shi zuwa Jamus, wanda aka gani a karo na karshe a 1942. Gwamnatin Romania ta kafa sabon babban birni a Iași kuma ta ci gaba da yaƙi a gefen Allied a 1917. Duk da kasancewar ɗan gajeren lokaci, kamfen ɗin Romania na 1916 ya ba da hutawa sosai ga Allies na Yammacin Turai, yayin da Jamusawa suka dakatar da duk sauran ayyukanta na kai hari don magance Romania. Bayan shan wahala a dabarun shan kashi a kan Romanians (wanda Rasha ta taimaka) a watan Yulin 1917 a Mărăști, Ƙasar Tsakiya ta kaddamar da hare-hare biyu, a Mărășești da Oituz. An ci nasarar hare-haren Jamus a Mărășești, tare da fursunonin Jamus daga baya sun gaya wa masu kama su na Romania cewa asarar Jamus sun yi yawa, kuma cewa "ba su ci karo da irin wannan tsayayyar tsayayya ba tun lokacin yakin Somme da Verdun". Har ila yau, hare-haren Austro-Hungarian a Oituz ya kasa. A ranar 22 ga Satumba, mai kula da kogin Austro-Hungarian "Enns" SMS "Inn" ya nutse ta hanyar ma'adinan Romania kusa da Brăila. Bayan da Rasha ta sanya hannu kan Yarjejeniyar Brest-Litovsk kuma ta fice daga Yaƙin, Rumaniya ta kasance kewaye da Tsakiyar Tsakiya kuma a ƙarshe ta sanya hannu kan irin wannan yarjejeniya a ranar 7 ga Mayu 1918. Duk da cewa an tilasta wa Romania ta ba da ƙasa ga Austria-Hungary da Bulgaria, Romania ta ƙare da samun riba a cikin ƙasa saboda Union tare da Bessarabia. A ranar 10 ga Nuwamba, Romania ta sake shiga Yaƙin kuma ta yi yaƙi da Hungary wanda ya ci gaba har zuwa watan Agusta 1919.