Géza II shi ne ɗan fari na Béla Makaho da matarsa, Helena ’yar Serbia.Sa’ad da mahaifinsa ya rasu, Géza yana ƙarami kuma ya soma sarauta a ƙarƙashin kulawar mahaifiyarsa da ɗan’uwanta Beloš.Boris Kalamanos, wanda ya riga ya yi iƙirarin sarautar Hungary a zamanin Béla Makafi, ya kama Pressburg (yanzu Bratislava a Slovakia) na ɗan lokaci tare da taimakon sojojin hayar Jamus a farkon shekara ta 1146. A ramuwar gayya, Géza, wanda ya girma a zamanin mulkinsa. A wannan shekarar, ta mamaye Ostiriya kuma ta fatattaki Henry Jasomirgott, Margrave na Austria, a yakin Fischa.Ko da yake dangantakar Jamus da Hungary ta ci gaba da yin tsami, amma ba a sami wata babbar arangama ba sa’ad da ‘yan Salibiyya na Jamus suka yi tattaki zuwa Hungary a watan Yuni na shekara ta 1147. Bayan watanni biyu, Louis VII na Faransa da ‘yan Salibiyyansa sun isa tare da Boris Kalamanos wanda ya yi ƙoƙarin cin gajiyar wannan yaƙin. dawo Hungary.Géza ya shiga kawancen da Louis VII da Roger II na Sicily suka kafa a kan Conrad III na Jamus da Sarkin Rumawa Manuel I Komnenos .Kakannin Saxon na Transylvanian sun zo Hungary a lokacin mulkin Géza.Jarumai na yammacin Turai da mayaka musulmi daga yankin Pontic suma sun zauna a Hungary a wannan lokacin.Géza har ma ya ƙyale sojojinsa musulmi su ɗauki ƙwaraƙwarai.Géza ya shiga aƙalla sau shida a yaƙin Kiev a madadin Iziaslav II na Kiev ko dai ta hanyar aika ƙarfafawa ko kuma da kansa ya jagoranci sojojinsa zuwa Kievan Rus tsakanin 1148 zuwa 1155. Ya kuma yi yaƙi da Daular Rumawa a madadinsa. abokansa, ciki har da 'yan uwansa, sarakunan Grand Principality na Serbia, amma ba su iya hana Rumawa daga mayar da suzerainty a kansu.An sami sabani tsakanin Géza da ’yan’uwansa, Stephen da Ladislaus, waɗanda suka gudu daga Hungary suka zauna a kotun Emperor Manuel a Konstantinoful.Géza ya goyi bayan Frederick I, Sarkin Roman Mai Tsarki, a kan Ƙungiyar Lombard tare da sojoji masu taimako tsakanin 1158 zuwa 1160.