In 1091 Ladislaus crossed the Drava river and conquered the entire province of Slavonia without encountering opposition, but his campaign was halted near the Iron Mountains (Mount Gvozd).
Aastal 1091 ületas László Drava jõe ja vallutas vastupanu kohtamata kogu Slavoonia provintsi, kuid tema kampaania peatati Raudmägedes (Gvozdi mägi).